I don't know, we used to be as close as you could get, but now she won't even tell me what's wrong. The only communication she has with me is by asking someone else to tell me.
That's difficult :/ i would just make sure they know that you're there for them, let them know that you know they're going through a hard time and you want them to know that you are there for them. if they dont want to tell you whats wrong, dont force them to, its up to them :)