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 needs with something on the menu or make something just for you. At the Quick Service restaurants you can ask for an ingredient listing to determine what is appropriate for the lactose intolerant members of your party, 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.