Tell her that macronutrient ratios do not matter as long as she is eating whole, natural foods according to her appetite. So she can have several pieces of fruit if she wants, but things like Quaker chocolate granola bars, not so much.
edit: Probably the less said the better. Teenagers are terrible with this kind of thing as body image and social pressures collide and make things all confusing. Just look how mixed up our own 14 year old "Gadsie" is.