Hi and welcome to NeuroTalk! So glad you joined us! I have MS, too, and there is a very large MS community here at NeuroTalk. Please join us in the MS Forum - I'm sure there are others who are dealing with or have dealt with similar circumstances as you are.
Your sister is fortunate to have you as her advocate. She's very young to have such problems. I truly hope things work out well for the both of you.