Help! How do I get my 10-year-old daughter to stop being such a picky eater?

My 10-year-old daughter will not eat what she is served. I cook breakfast, lunch, and dinner and the girl will not eat. I end up having to make something she will eat, or I tell her to grab something herself. My other child eats with no problem. We have eliminated the possibility of a medical problem, we have tried just about everything I can think of. We have consulted her pediatrician, an eating specialist and she still refuses to eat anything other than what she wants. Unfortunately, what she wants is just about nothing save push-ups, garlic cheese bread, and peanut butter (not real healthy choices). Anyone have any suggestions?