Amanda,
Yes, there's a lot of gluten-free food available! Every restaurant in WDW should be able to accomodate you if you have food allergies. All you have to do is indicate what those allergies are when you make your "advance reservations" and the CM will give you the phone number to a chef at each restaurant. You should call each chef at least one week prior to your arrival. He/She will discuss food options with you, including dessert, and you can make special requests too. They will always accomodate you when it's possible. Some things have to be special ordered which is why it's important to call a week in advance! My DS did have a wheat/gluten allergy but outgrew it! He continues to be allergic to nuts and eggs. :0(