I do feel sad for the op because she is obviously hurting so much. Whether she is justified or not is another matter but I'm not judging.
Elephantinbed, it sounds as though you and your siblings inherited a decent amount from your father. You don't need you mother's money but I imagine there will be something left for you when she dies, she's just going to spend in the here and now.
She may never be immobile, you know, not all elderly people are handicapped in old age, some are fine and then die after a short illness. Something I think we would all like for ourselves. In the case of being helpless, I expect your mother has something in place for that.
Feeling bitter against your mother is not doing your health any good - I'm sure you know that. It will eat you up and in the end, your attitude could be far worse than the person you're angry with.
Your mother and father made you the independent people that you are. There's no such being as a perfect parent, we all get it wrong. I'm sure they loved you and believed everything they did was for the best in the long run. You've said you enjoyed school and all that. You've had a more interesting life than many. Mum may not be the type of mother you want but she doesn't sound like a bad person and, in time, you may find she is a lot better than you give her credit for.
This is going to take its own time: I think it would be a good idea for you to go to counselling - Cruise might suit because your father's death and your mother's 'attitude', so close together, are intertwined in your sub and unconscious. Being able to talk it out face to face with somebody neutral can be very helpful and a good therapist will guide you but not tell you what to do. In time your attitude will soften and what seems like a big deal right now will just be a period of your life.
All the very best to you and thank you for sharing, it's making a very interesting and unusual thread.