Hello greentires: I don't really have any suggestions for you here.

Your sister probably should start with her medical provider, whoever that is... physician, clinic, or other. (I see you're in Canada. I don't know how these sorts of things like this work where you are.) As I presume you realize, unless your sister wants help, there's really nothing you can do to make it happen.

My condolences on the loss of your father...