Originally posted by catland
She is blessed to have you as a friend since you care about what happens to her.

Talk about this to your mom or another trusted grown-up. That is what they are there for.
I agree with this approach. It will probably take an involved
adult somewhere along the line to get her help, if she needs it.
If you really don't know this girl, how do you know if she has
medical problems or what they might be? She does seem very
thin to me, BUT, it could be a lot of things.