Hi - I am not vegan (pescatarian) but my wife and 2 children are. My wife has been vegan for around 15 years and has been vegetarian since she was 14. My boys have been vegan since birth (11 and 9 years).
Provided no risk of possible health impact (i.e. insisting on Vit K injections and vaccines; ensuring all nutrients correct etc), I was fine with my wife’s preference, in part as she has been their primary day to day carer and is the one cooking for them predominantly. I wouldn’t ask her to cook meat or fish for me or anyone else - if I want that, I sort myself or have when I am out.
I worried a bit about social isolation at school and so on, which is a bit vain but that turned out to be a non-issue in any event, as plenty of other children had food allergies or religious requirements, and friends’ parents were v good.
From a health standpoint, it requires parents/people to be much more astute to nutrition (ensuring adequate sources of vitamin B12 for example); having said that, my wife and kids are fantastically healthy - strong, fit (my wife is in her 40s and is much fitter than people 10 years younger, and my kids are super active), and (when tested) with excellent bloods. Their diet on the whole - probably because my wife has had to be so much more on the ball with it - is by and large much healthier than that of their contemporaries whose parents/partners have a standard diet and don’t need to think about it.
That’s the long point! Shorter one is: it’s a potentially fraught subject, with no totally right answer, but if you’re doing the cooking, your wishes should carry more weight. Unless your husband has an ethical objection to vegetarianism or Veganism (or a plant-based diet), which only you can really parse with him (and then perhaps he can cook the meat or feed them), then the health outcomes shouldn’t concern you - you can have a fully balanced and entirely plant based diet with all essential amino acids and similar. However, it does require some research and care.