Nana46, I find your comments to be very rude. Who made you the boss of judging other people problems?? Don't be so stuck up!!
Bad B.O is very unpleasant, I can't even stand by someone on the tube with it for a short journey, let alone live with someone that has it. So I can totally sympathise with you.
I suggest you could maybe buy her a lovely hamper full of nice soaps, shampoos, deodorants maybe add some body sprays and perfume. You could also put some of those sweet smelling bags of lavender in her draws to make her clothes smell nice .
And just have a little chat with her about it. Hope you get it all worked out