Hi Florida mom,
Diet is so important for kids and it seems like almost every food geared towards kids is bad for them. Unless you have your daughter tested for allergies it's hard to know what and what not to feed her. The biggest culprits I have found so far are "artificial food colorings" (not sugar), "deli meats or processed meats", "MSG",
"artificial sweetners" & "processed cheese". Even if kids can tolerate these "foods", they are not good for them. These are a good bunch to cut out altogether.
Start keeping a log of everything you feed her and how she acts afterward. Dairy is fine for my kids although I try to buy organic products.
It's hard keeping small children on a healthy diet so you might have to get creative. Try to include your daughter in the "fun" preparation of her food and make it look "pretty" with colorful veggies and fruits. Be prepared for a big mess...