Going with group of 3rd graders anything you can suggest to help me make this an additionally cool field trip/ experience/ memory?

If you can make sure to set the kids up with questions for the Q and A after the show. The theater is nice just a little bit of preteaching should cover the rest. I took my 7th graders and had them write a review. Some had awesome insights that I had missed.

Call ahead and coordinate with the theater. The B St theater loves kids! Great group of people.