I live right near there.

Let's see:
Sesame Place is at an entrance to Oxford Valley Mall...Inside the circle around the mall you will find
Red Robin -- Lettuce wrapped Protein Burgers and gluten-free fries
Cheeburger/Cheeburger -- create your own salads (yum!) and they will wipe down the malt/shake machine for you to make a terrific banana shake (or other flavor)....I've eaten there several times and been fine
Cheeseburger in Paradise -- They have a gluten-free menu online....If you are particular with requests to avoid cc, you will be fine.
Across the street from the mall, you will find
Chili's they have a few gluten-free menu items.
There's a Don Pablo's nearby but I've been contaminated each time - I would recommend avoiding it!
If you are willing to drive a little farther away from the park, I can give you a few other suggestions.
Enjoy the trip!
Oops - I forgot, if you find yourself in a bind - leave Sesame Place and turn left onto Oxford Valley Road - go straight over Route 1 and on your right you'll see a Kohls (it's not far at all). In the Kohl's shopping center is a Superfresh with terrific produce section and an organic aisle, too.