How to help a teen friend with a very hard life...?

my friend .. she was told by a docter that her mother is going to die.. she wont tell me whats wrong exactly.. but she has been devistated.. she said that the docters dont know when she will die but she has. bad nightmares and just the reagular grieving. she also has had 3 concussions in one year and just now got over one of those concussions... anndd she just feels depressed i guess... why are people cursed with this..