Disney is very considerate of food allergies in general. You will want to note the allergy on any of your dining reservations, and when you are seated you should be consulted by the chef (if not ask for the chef). They will accommodate your allergy needs with something on the menu or create a just for you. At the Quick Service restaurants you can ask for an ingredient listing to determine what is appropriate for the allergy needs of your child, sometimes you may speak to a chef there as well. Disney also has a new kiosk in the Animal Kingdom Park to address food allergies with snacks, nutritional information, etc. The chocolate and apple allergy should be simple enough to avoid, but Disney will definitely work with you to make sure there are lactose free options that your child will enjoy.