Hi T., I can totally relate, my son will be 2 in 2wks and is just starting to eat well. Like your daughter he loves fruit, but I too was concerned that he wasn't getting enough nutrients. Have you tried giving her a protein shake (they have pediasure now), but I always used mix I bought at Nutrition Depot and added a banana or fruit to it & Preston just loves it.
For meat I usually bread chix cutlets (or buy Perdue shaped nuggets) and I'll give him dip (ketchup, marinara,ranch, bbq sauce) that seems to be working - but before then I'd just use a chopper and put some roast chicken and mince it and mix that in w/pasta, mac n cheese (I'm not crazy about him having that but buy Amy's Frozen Organic)
As far as school, what about mini bagels w/cream cheese, cut up melon/fruit, veggies, shakes or smoothies, roll ups of deli meat (buy the low salt ham -Boar's Head makes one)w/cheese, cold pasta (penne or rigatoni shaped), did you try peanut butter sandwich yet?, ritz cracker sandwiches or mini burgers.
Hope some of these work!!! It certainly is difficult & I know how frustrating it is when they don't eat, but I promise it will get better. According to books/drs. you have to introduce new things 14 times before they'll try it!!! Good luck,
K.