I highly recommend splitting meals! We do this at almost every counter service, and we sometimes even have food left over. We share two adult meals between myself, DH and our two DDs. I would say we are average eaters, except for my youngest DD who is capable of eating her own body weight (yet is still somehow small for her age. Wish I had that ability!).
My suggestion would be to share something like chicken at Plaza Inn or soup in a bread bowl (the corn chowder at Pacific Wharf is our favorite, as is the shrimp Louis salad). Then, if you are still hungry, you can try one of the awesome snacks! It's important to leave room for churros, Mickey pretzels, chimichangas, etc.