your friend/family has a severe anorexia what would you dotohelp her?

I do have a friend who's anorexic. We aren't that close friends but still we are friends. I don't know how she does it. I mean she never eats and that is not because she wants to get slim. She is very lean already actually. She tells me she can't eat and doesn't feel like eating. I've never seen her eat actually, maybe once or twice only. But she drinks a lot of herbal tea and stuffs.

Anorexia is something serious. First, i would try to talk with my friend on how i perceive her so being thin. I would really discourage her from being that and tell her what it could lead her to. If despite my having talked with her about it, she would still insist , then i would really accompany her to the doctor, who could really help her in fighting it.