Hi My Oldest Sister Came Very Sick And Was Taking

Hi my oldest sister came very sick and was taking to hospital, she had like 4 strokes in a few days, that's when they found that she had moyamoya, she's going for a brain cooperated on.they say it's a 50/50 that she comes out off it. I'm not sure if my other sister, Who is a twin to the one with moyamoya and I should get check out for it. As my family tree for females is very bad, like bad blood lines heart trouble and getting no by parts cut off strokes. We r wondering what to do. Thanks you.
KELLY