How about making her a few cheese chips. Use her favorite cheese. Put 1/4 ounce pieces on a stick free surface (I use no stick foil) and bake at 350 degrees for 10-15 minutes. Different cheeses take different times. The low carb bread or rolls would offer a lot of lunch menus and at 11 years of age, the few extra (good) carbs would not be a bad thing. Cold chicken such as low carb fried or bar-b-q would be nice. Celery stuffed with cream cheese or natural peanut butter (the regular stuff is full of sugar).