Anna, I'm sorry to hear that. I have no experience with a friend dying of an illness, but it's always tragic when such a young person has to die.
I do have two friends with heart problems. One of them, my brother's ex-girlfriend, had to undergo heart surgery when she was just a child and now has a checkup every year. His current girlfriend has a (rare?) disease which also has to do with her heart and for that reason it could be too dangerous for her to have children (because of labour being too much for her to handle).
I hope your friend can still enjoy her last few months, and maybe do some things she's always wanted to do. And unlike with car crashes, you can make the most of those last months and say goodbye in your own way.
