Here are some lunch ideas:
I find so many good recipes on glutenfreefix.com. Her Parmesan Crusted Chicken would be a good thing to bring. She also has a good pita bread recipe. You can stuff it with her BBQ chicken recipe, eggsalad, or chicken with Wellbees mayonnaise.
I also like to cook 100% beef burgers, melt sliced cheddar cheese on them, and cut them into strips. The cheeseburger strips are good dipped in a dip made from mustard (You can find legal mustard easily), Wellbees ketchup, and Wellbees Mayonnaise.
You can also make an egg casserole with meat, veggies, etc. If your daughter likes salad, that is another easy meal you can send her with. Gluten Free Fix has great dessert recipes also!
Hope this helps!