Disney says
Served with seasonal vegetables, fruit cup and choice of Small Lowfat Milk or Small DASANI® Water.
Friendliest.app says
The oven-roasted chicken is free of the top 8 allergens (gluten/wheat, milk, fish, shellfish, peanuts, tree nuts, eggs and soy) when ordered with water.

Other sides include vegetable crudités, baked beans and potato bites, but introduce additional allergens.