I know that Monsters cafe, Circus McGurkus Cafe Stoopendous, International Film & Food Festival and a bunch of others offer salads and vegitable sides (broccoli, corn, etc). IF&FF even has a fresh fruit plate that is included with the meal deal and I think it's monsters cafe that has rotisserie chicken on the menu.
Mels and I think the Cafe in Marvel Island have grilled chicken sandwiches-you could just eat the meat.
As far as for children, esp. if you're using the meal deal, your options are more limited, because most of the kids items are heavily reliant on starches--fried mac-n-cheese, burgers and fries, spaghetti, etc.
Most places also offer jello for desert, as well as fresh grapes (though grapes are usually not listed).
Other than that, I think it'd be a great idea to give the park a ring and get it striaght from the horses mouth.