The thing is that @grabbie isn't going to go hungry. Sadly if she has to give up work, her children will have to go to a state school and they might have to (horrified intake of breath) get some part-time work to help them through university. Although we still haven't actually had any explanation about why "struggling with mobility" = "can't work". I managed perfectly fine for years before I retired (late). Still could work if I wanted to. If I were going to ask for anything, I think I would go for help with aids or retraining so that I cam continue to work and stand on my own two feet (figuratively speaking - I often fall over if I try standing on my own two feet!).
But I do agree about getting "too much". A close friend of mine made a killing in the early days of home computing - sold his company to Microsoft and landed £millions in his bank account so never needed to work again. He got a very nice house (in the area they already lived in), sent his kids to private school, and gave the kids a modest allowance - enough to "get by comfortably" without being flashy. He stayed down to earth - generous to friends and others, without being showy. He taught his kids the value of working, and the benefit of using money wisely.
Long story short, they decided by 13 / 14 that they'd inherit enough to never work, pissed about at school until they were expelled, then again at another school and also at a third one. Spent their money on drugs and alcohol. He did everything he could. Rehab, counselling - and believe me, he was a fabulous, caring father; and their mother was just great, Those kids were not "taken to stately homes" or left to their own devices. When they hit 20, with nothing left to love or support, he disinherited them (and after many warnings he would). Left his fortune to drug rehab charities. I'm glad he didn't live to see his eldest son die of an overdose, or his youngest (as far as we last know) a homeless addict in and out of prison.
Money and advantage do not make people. They can help. But nobody needs a private school or even university - although anyone willing to put in the effort can get to university now. The OP can, assuming this is all true, provide a stable and loving home and the support to grow confident and capable children. Nobody needs money to do that. My parents had nothing. I have a degree and three postgraduate qualifications, and a succesful career. It didn't need a private education or money to produce that - but it needed support, values and life lessons. I got those a plenty - especially from my mother.