how to help a friend

So I'm new to the site. I already got some great feedback for my own issues picking my face. (still makes me cringe to write that) I also have a friend who has started chewing at her fingers. I hadn't connected it to the same kind of problem that I had until I read entries on this site. Now I'm wondering how I can help her. Honestly, I would be mortified if anybody tried to talk to me directly about my face, so I don't know if I should address this directly with her or not. I have covered her hand with mine to get her to stop, and probably reminded her myself. But I was thinking more of it as a habit. Now its so obviously a compulsion for her. And it is very much related to stress. She's in an ugly custody battle with an abusive ex, and she chews away at her fingers in court. I worry about her fingers, and how this looks to the judge. What can I do? I've learned from the site that moisturizers sometimes help. What else works. And more importantly, how do I broach the topic. Should I talk about my own problem. Again, mortified. But she is my best friend, so I will if that's best for her. I would rather disclose just about anything else, and I have to her. Any advice? How would you want a friend to help you? - K