Is my friend anorexic?

Hi, my name’s Sarah. One of my best friends, I think may be somewhat anorexic. She’s 5’3 and three weeks ago weighed 160 (yes she was a little overweight but she didn’t look huge, like if you were to just see her in a store you wouldn’t think “she’s so fat” you would just think “she’s fine.. MAYBE a little overweight perhaps) anyway, she does exersize healthy. She does a school sport from 3-5 monday-friday. She doesn’t eat breakfast (anymore, she did last month and before then..) and she doesn’t take lunch in school because she takes extra honors classes. She eats dinner but that’s all, and I’m not at home with her for dinner, so I don’t know if she trows it up after but she’s loosing a lot of weight. She weighs 140 now and I’m getting worried, she looks great now and is at a healthy weight however she thinks she is obese and wants to continue dieting, im not saying she shouldn’t but the way she isn’t healthy, what I mean by that is she sends me all these pics on aim of girls who are WAY to skinnny!!! and says that’s her goal, she says she eats breakfast (to our teachers, who have gotton somewhat suspitious) but says she doesn’t to her friends (such as me) Any advice?