Thank you to everyone who replied - your answers have really helped me organise my thoughts.

I'm going to sit down and talk through the problem with my DH later this week.

We've spoken before at length but I've been trying to persuade him to my side of the argument without me properly explaining the feelings behind the discussions. I can now see that these are as important.

Thank you again.

I think we need to take the OP at her word that they can afford it. Although the cost of private school makes it unattainable for most, for some it's something that is readily affordable. A six figure gift to these families may well have the same impact in terms of relationships any family dynamics as £500 to others.

It really is about principles and values, as well as some important practical financial ramifications.

Here's my two pence:
1. Personally I feel that unless it's a matter of life or death (or serious risk to life or wellbeing) - money and extended family do not mix. In my experience family loans/ gifts almost always end up with unforeseen negative consequences.

2. I believe reliance on a well off family member discourages people from sorting out the core of their problem, which is often, even if not immediately in their own power to change. I suspect that if your sister wanted to keep the kids in private school, she'd find a way.

3. Again, from observing others' experiences it is crucial that your sister fights hard for the best possible divorce settlement. Your interference is likely to muddy the waters and could turn out to make things worse for your sister and the kids in the long term.

4. Your sister will always be your sister. If you have the kind of bond you describe, I bet you will get through this and in hindsight it will seem like just another hurdle on life's path.

5. My parents (who had a long and happy marriage) always said that if they couldn't both agree, the default was the status quo (i.e. Not do the thing that provoked the contention.) I personally think this is very wise, particularly in your situation - as once you commit the cash, you are essentially accountable for what transpires (and there is a good chance there will be unforeseen negative consequences), whereas if you kindly leave others to fight their own battles, firstly, they may remedy them themselves and secondly you are still in a position to potentially help if circumstances worsten to an extent that a different decision becomes the obvious one.

In essence, I think what I am trying to say is be careful of interfering. Your marriage may not be the only casualty.

Could you offer a payment plan+contribution? She can presumably afford part of the school fees If they've been able to stretch to the whole lot.

Let's say she can afford 20%. You gift a percentage, let's say 25%, then she borrows the 55%. This is then repaid over a longer period of time. Your sister might want to take this offer up for a year or until they finish st their school and then transfer them into the state sector for secondary school. She then continues to pay off the money borrowed.

Circumstances can change, even those of multi millionaires. What would happen if you and your husband lost all your money and you'd paid the school fees? I'd imagine that would cause huge resentment.

What job do you have? How much can you contribute?

I totaly understand your wanting to help your sister, but the children's father is ultimately responsible for providing for his children, whether he accepts it or not. Also, if the financial situation is not good, why are they in a private school in the first place? At the end of the day, it's never a good idea to have financial dealings with family...it's a sure recipe for family break-ups.

I've read through all the replies, and here's my view.

1) This is clearly NOT a debate about state vs private education. It's about the OP's wish to keep her sister's children in their school, where they are happy, amidst the unsettling time they are facing and to give them stability at school, with their friends.

2) I agree it is not the OP's 'right' to demand her husband pays the fees, but as husband and wife, joint decisions about how to spend money should be made. I'd be very interested to know how people would feel if they OP (a woman), earnt all the money, her husband didn't work, and he didn't want to pay fees?

3) Helping out families is what families do (or should do). I think it's quite appalling that so many of you think the OP is out of order for considering helping her sister. Of course it is a HUGE financial responsibility, but she said they could afford it. If we were in a similar position, I would absolutely be considering the same. Interestingly, I asked my husband, who is the main breadwinner in our family, and he was absolutely of the view that we would help our siblings in a similar situation if we could.

Anyway, I could go on, but I don't think your husband is right to dismiss it out of hand. You need to have a long discussion, and think about the repercussions for both scenarios. I do have some sympathy with your husband also, because as others have said, it is a lot of money, but what's more important, your nieces and nephews happiness at a time where their world is being turned upside down, or being able to retire early or go on a few nice holidays?! Really?! I will also say that I believe moving schools is a huge disruption for a child, never mind about when it's happening at a time when things are bad at home. I went to 4 different primary schools as a child, and it was awful- it massively affected my education and confidence.

Good luck, I hope you resolve this, and well done for being such a considerate sister!

I think the concern for me if I was in your husband's shoes is the long-term dependency.

In effect, the responsibility for the children's long term stability (educationally) would sit with your husband. If, for whatever reason, he felt he would no longer be in a position to pay the fees somewhere down the line, then he would end up being the cause of destabilsing the children, when in fact, it was their parents divorce that did that years before.

Asking anyone, even grandparents, to take responsibility for the education of your children is a massive undertaking and should not be taken lightly.

What if you were to help in another way which would enable her to pay the fees herself? Could you perhaps help buy her house? Her car? Something that wasn't as emotionally driven as her children's education?

HelpPlease - I think your intentions are really nice, however I feel you are approaching this in a way that is not fair to your husband.

Why don't you discuss with your husband what you are both happy to do to help your sister?
It may be that he is happy for you to pay for next year's fees - which I agree would be very good for the children as they will at least have something constant in their lives.
You may also decide that you are happy to contribute something every month towards their education (and maybe save on something else - clothes, going out, hairdresser, etc).

Also, how sure are you that your husband can easily afford 65k a year (pretax), every year for however many years they have left (you don't mention)??? It's a huge commitment, and even if he earns a lot of money it still means he may have to retire later, or not afford the car he wants, etc. And what happens if he loses his job or his earnings drop (as there is at the moment quite a lot of economic uncertainty)?

Finally, as soon as you both decide what you can help with, I would have a conversation with your sister, so she knows what financial help she can expect from you. This may make her look push for a better divorce settlement with her ex, or start looking into decent state school options, or start planning her finances so she can do state primary school and secondary private school.

I cant see why this would change your relationship with her, you'd still be there for her when she needs you, you just can't be her cashpoint too... Maybe the idea that you not paying the school fees would ruin the relationship is just in your head?

Best of luck, I am sure you can find a compromise with your husband.

I have a huge amount of sympathy with the OP and her sister. As the OP said in her original post the desire to keep the children in their school is to provide some continuity for them at an extremely difficult time - this is not about about state v private - it just so happens they are in a private school but it sounds like the overriding thing here is trying to keep them in the environment they know, with their friends and teachers through a time when the rest of their world might be crumbling. It must be heart breaking in a divorce situation to inflict changing schools on your kids at the same time as everything else. The OP doesn't say how long her sister would need help for - as others have said perhaps there is way to compromise - to help for 6 months or even a couple of years whilst she sorts things out with her ex and her own financial situation.

Confus_ed wrote: Prep school fees are about £18k per year per child. If the poster's husband is earning 500k a year (salaries that hugh or higher are not unheard of around here) then paying fees for his sister in laws kids would mean giving about 7% of his annual salary.

Not quite. £36k net in annual school fees is somewhere around £65k in pre-tax earnings, which would be closer to 13% of those earnings - almost double. Add in a mortgage and other expenses (again out of net available cash) and the ask is a still a big one. It's £325k over 5 years.

I think the basic issue is being lost because of it being private school fees that are at issue which is always controversial. Look back at the original post - she's not saying private schools are better or that a state wouldn't be good. Nor is it about needing a certain standard of living. She's worried about the effect moving schools and leaving friends behind will have on the kids when it is happening at the same time as a huge upheaval in their home lives. Not an unreasonable or unrealistic concern.

Prep school fees are about £18k per year per child. If the poster's husband is earning 500k a year (salaries that hugh or higher are not unheard of around here) then paying fees for his sister in laws kids would mean giving about 7% of his annual salary.

It's entirely relative - if her husband's salary is that high then it isn't a huge amount.

If it were my sister I'd also feel a desire to help. We are fortunate enough to be in a position where we could do it without having to make any sacrifices and I know my husband wouldn't object.

Could you suggest offering a year's fees for now so that any move can happen a while after the split once the kids home life is less uncertain? This would also have the advantage of preserving your sister's position in any financial proceedings on divorce.

So my kids go to a state school as, in part, I was reluctant to send them to a private school when I was insufficiently sure about my future income stream to commit......

That aside, I disagree with other posters. My sister split up from her partner and wanted me to buy a house for her and her kids that she would pay some sort of rent towards. We could afford it but my husband was against it. Instead, I helped he to get a new build housing association house which is lovely and she is happy in. But I felt very resentful towards my husband and I wanted to help her, because she was my sister and I could. Most of this was me feeling like I should help her, she wasn't expecting it, but I wanted to help as she was my sister. In my case, I may well done it anyway and accepted the wrath of my husband because if he loves me then he accepts me and part of me is how I feel about family.

Luckily we sorted something else out and I have to say I am relieved not to have bought the house as I think it would have changed the dynamic between my si and me, as well as my husband and me, forever.

But in your position, if nothing else can be arranged, I would probably pay because it would mean so much to her. And she is your sister.

Thank you to everyone who has replied, this has been very helpful.

I wanted to answer a couple of the questions raised.

I think your intentions are lovely but to be frank you seem to be underestimating what a massive "ask" this is.

I know it is a massive ask but we can afford it. If it was in the slightest part a constraint on our finances I wouldn't be contemplating this.

cannot afford the school fees now then how did her sister and brother pay them previously. People's income doesn't vanish just because they separate/divorce.

They just managed to pay them but it was a struggle. Running two homes will make it impossible.

Thank you again.

I'm a bit surprised by some of what the original poster says.

First, it doesn't seem that there is any contemplation that state schooling might be an acceptable alternative to independent schooling. If we were told that there are no good state school options accessible that might make us more sympathetic. Similarly, if we were told one of the children is in year 9 or 10 and just has two/three and a half more years to go and they don't want to move him/her I think we would have more sympathy.

Secondly, if the original poster's (soon to be ex-)brother-in-law cannot afford the school fees now then how did her sister and brother pay them previously. People's income doesn't vanish just because they separate/divorce. The costs do go up if two separate households are being maintained but for a family that is already financially able to pay two sets of independent school fees the cost of a father moving out and renting a one bed flat shouldn't result in a cost equivalent to two full sets of independent school fees. Would the original poster's sister and brother-in-law have been able to keep paying the school fees if they had stayed together? For me at least, something doesn't add up here.

I have to agree with the previous poster. It is not about whether or not you/your husband can afford it, it is more about your sister no longer being able to afford the lifestyle she would like and I'm afraid that is not anyone's problem but her own and only she can address it. To do otherwise is not a workable long term solution for anyone involved.

This is a big no no. From what you have said, it basically boils down to your sister not being able to afford to send her kids private in the divorced set up. It doesn't sound like a temporary cash flow problem, and therefore you would be effectively propping her up to live beyond her means. I am with your husband on this one. I'm sorry, but your sister needs to accept the hand she has been dealt and realise that her means no longer extend to private schools. If that presents an issue, then it is up to her to find the means not rely on your hand outs.

If you were to give her any money, then every new pair of shoes she buys and every holiday her family go on, you will be questioning as in the back of your mind was that a necessary purchase and should she be buying such things when you are propping her up? This will eat away at your relationship with her more than you realise and probably ruin your marriage. Its just not worth it.