Last Nov/Dec I took my 11 yr old god daughter with me. She eats "adult" food but was unsure about things like sauces or toppings. There was never any problem ordering the food plain - We ate at Le Cellier, Alfredos, Concourse Steakhouse, Planet Hollywood, The castle, and Mom's diner.
I don't think you would have any problems, disney does tend to be very accomadating.