Boopers, this is a touchy subjet.
Part of me is looking at her like a really selfish person, I don't like when people don't share with others the fortunes in life.
If I was her I wouldn't ask for the money back at all, but obviusly there was some miscomunication. Now, why is her daugther letting you, guys, know about all this? I think the mother is the one who needs to talk to you. This is a private matter and I think when there are a lot of people involved, that tends to complicate things.
Also, i think the money is an issue, but feelings hurt because of your illnes is a different story.
If you really want her to care, you need to let her know.
But is my sugetion that maybe you need to separate the issues and with a clear head, talk frankly to her.
In any case, best of luck to you hon, PM me if you need a ear~