I am somewhat the same way. I always notice what people shop for, order, and eat. Not sure if it is a function of being conscious of health and weight or if I am just a people-watcher, probably both
I guess my rule is, think what you want, but be careful what you say. With food as with anything in life, not everyone thinks the way you do and we all have a right to different opinions.
Yeah, sometimes I
look at people's plates and think that it's not fair that they "get to" eat all those carbs, sugar, fat, etc. That's when I have to remember what I'm doing this for.
Your reward will be your child making better choices one day on her own. Maybe you could explain it to her once you are out of the situation. It's also possible that her healthier eating habits could be a good model for her friends.
One thing that worked with my son (he's 13) was the garbage-in-garbage-out theory. If he eats too much junk, his sports performance won't be as good as it could be.
In fact, yesterday a rainbow came forth in my family room and angels sang...he bypassed the three boxes of Quaker granola bars in the pantry and took a Kashi bar. Later that evening he asked if we could have something besides hamburgers because "they're not that good for you." So I know it is getting through on some level. I just explained that extra lean ground beef on a whole wheat roll isn't going to be the end of the world and smiled to myself.