help!?

My sister has experienced stroke symptoms last week. Her right side of her face and her arm went numb and she was not able to speak without a slur. She had 4 tests ran on her. A catskan, 2d echo, mri and a mra. She found out that the valves in her heart are leaking and one is leaking quite moderatly. What does this mean? how can it be fixed? can it get worse? what can i do to help? does she have to have surgery?
She means the world to me, i need to know more about this. She is a nurse so I think she is hiding stuff from me so that i dont get hurt.

please help!!!