W.P.
I've been packing my daughter's preschool lunch for the past 2 years, and her school has almost the same rules as yours (no nuts, no refrigerator, no cooking of meals). I bought her an insulated lunch bag (easy to find) and 2 good cold packs (Prince Lionheart Reuseable Hot & Cold Packs - from Babies R Us). I always keep them in the freezer & alternate them in her lunch bag. (I always put the cold packs in a ziploc bag to guard against leaking & melting ice pieces that could make lunch soggy.) She loves yogurt in her lunch bag (Stonyfield Farm YoKids - either a cup or tube/squeezer), as well as applesauce. I also make sandwiches for her (no pb&j). My daughter really likes when I make her sandwiches with the Pepperidge Farm Goldfish Bread (comes in white or wheat). If your girls like hummus, pairing it with some crackers is also a good choice. My daughter's school/teachers normally won't heat up lunches, so I always have to pack food that's usually served cold or at room temp. Cheese sticks, healthy granola/snack bars, fruit strips/fruit snacks, pretzels and goldfish crackers are some of the 'sides' (in addition to fresh fruit) that my daughter enjoys with her lunch. Raw carrots are not allowed in my daughter's school due to the choking hazard they pose. Good luck to your daughters in their new preschool!