Some years back, I assisted at a photo shoot for a Little League team, and the boys were a restless crew. The photographer was patient and had humor, but he was getting a tad frustrated for the group shot. For no particular reason, I stuck two fingers, bunny-ear style, over his head while he focused for yet another shot - and it worked! Suddenly the kids were sitting up and looking right at him, giggling but not wanting him to know he was the butt of my teasing, and so they obeyed when he said, "Look at the camera, guys...okay, on two...." And he ended up with a couple of really cute shots with a happy laughing little team. I only told him later what I'd done.
I'm not particularly suggesting you get someone to try this - just a memory I have when dealing with a squirmy group of kids and how it suddenly got better.
Congrats on the gig - go have fun with it!
