Hi Skyla,
I have to agree with Chy. Unfortunately, all you can do for her now is pray. As for not hanging out with your other friends because you want to keep an eye on her, I say don't quit your other friends. Maybe if you let go of the friendship a little, she may see there's a problem. I'm not saying to forget about her, but maybe take a few steps back. There's a friends and family forum here also that may be helpful to you. Look around and check out other posts. We will be praying for you and your friend.
Sherry