Another option rather than splitting an adult meal some restaurants like Le Cellier have a kids meal w/ steak, and Tutto Italia has grilled chicken and vegies, or pasta w/ a parmesan cream sauce. I appreciated these added options to the standard "kid" fare which my son would never eat! I don't think there is anything worse than Disney pizza and Disney mac & chesse, yuck, this is where Disney really needs pixie dust!
My son at 3 loved the vegetable cous-cous at Marrakesh, now (14) he eats the beef kabobs. The restaurant is lovely, with music and belly dancers, it's a fun experience.
San Angel is also a lovely restaurant, and we would order a couple of appetizers with our meal and my son would make a meal out of them. Seeing the boats go by,, the music the decor, something different!
Tepan Edo (Japanese GHibachi grill) has a kids meal with rice and chicken or shrimp, just like the adults and the show the chef puts on is cool!
If you head to DTD, T-Rex is a fun place for both kids and adults, and I think the food is good! Their kids menu has ribs, popcorn shrimp and rotiserrie chicken.
My son even now loves Sci-Fi, sitting in those cars, who am I kidding, we like it too, the burgers and shakes are very good!
We only like 2 buffets, Boma and the Tusker House Character Breakfast buffets, the best of Disney IMO!
Remember that any Disney restaurant will prepare typical adult meals like steak, chicken or fish simply seasoned w/ salt and pepper rather than sauced or spiced as described on the menu, you just have to ask! I've always appreciated restaurants that encorporated what is considered "adult" food (IMO, food is food ) into the kids menues! If there wasn't anything on the kids menu he liked, he picked from the regular menu or ate part of mine!
Have a great time in September!