That's cool, hope he gets one.
My little girl was a little apprehensive about shooting the new 20ga also. Once I talked her into trying it. I poured all but abut 1\3oz of the shot out of some dove loads and packed the shell with paper. I shook up some sprite cans and set them out. I had her sitting between my legs as if we were hunting. She was timid at first so I just told her close her eyes and pull the trigger, I promised her I wouldn't do anything that would hurt her. She missed the can her first shot, the next 3 she sent sprite and parts of cans flying everywhere. She was grinning ear to ear.
I've found with young kids or anyone that is just starting out its better to have some sort of visual reward for hitting your target. Most everyone likes things that blow up, be it sprite cans or pumpkins filled with water. Heck Im 35 and I still love blowing stuff up,lol