Hi Rebecca, and welcome to the Disney Parks Moms Panel!
When it comes to picky eaters, I feel your pain, Rebecca. My 5-year-old son is a cheeseburger-pizza-chicken nugget kind of kid. With rare exceptions (he loves tomatoes, oddly enough), we rarely deviate from that rotation. In our case, we tend to eat mostly quick-service or counter-service meals at Walt Disney World, so we can usually find something he likes.
I've found that the menus listed on the Walt Disney World website don't always give me the kind of detail I might be looking for. You'll get the name of a dish, but not always a complete description or a listing of sides that may come with your meal. My favorite website for more detailed menus for Walt Disney World dining is AllEars.net. From their homepage, go to the "Walt Disney World" tab near the top of the page, then select "Dining" from the dropdown menu. Go to "Menus" and you'll find a complete listing of pretty much every single bite of food available at Walt Disney World. Cool, huh?
As far as finding something your picky child will eat, I think you'll find that most of the table-service restaurants will do their best to help you. Just ask your server if something can be modified (say, pasta without sauce), and I'm sure they'll be able to do something for you. The quick-service locations can probably be less flexible, so do check out those menus in that case.
Eating at Walt Disney World is an adventure all its own, and I hope this helps you find meals your whole family will enjoy, Rebecca. Please stop by again if you have any more questions. We love to help!
Have a magical day,
Kathy K.