This will be a very touchy subject to your friend if she does indeed have an eating disorder. I battled with anorexia for 7 years. It wasn't pretty and I lost alot of friends who tried to help me. Things got really bad for my parents. I was in and out of the hospital for 7 years. Not only is my immune system still suffering from it, but the disease has left many other "scars." The worst of them is my obsession with my weight. I will never get over it.

Talking to your friend may not be the right approach since she will probably turn you away. (People with eating disorders do not want to be helped. They are in denial.) It makes me wonder where her parents are. I would probably be dead today if it weren't for my parents. They battled the disease with me! You say she eats chips and drinks. Then she is most likely Bulimic.

I am not sure if you can trust the councelor at school to keep your concern confidential. Perhaps voicing your worries to them would make them contact her parents and hopefully get that poor girl some help!

Best of luck to you.