Sitka Deer,
My oldest shows no signs of being recoil shy so far, he's shot my full size model 11 several dozen times at Clay's ( broken a dozen or so too!!) I noticed the single shot's comb being pretty low upon initial inspection. When I give it to him at Christmas we'll adjust length of pull for him and consider some type of cheek piece if necessary. I'm also looking into lighter loads for Clay's and small game.

Since we're discussing "first guns", my younger two at 4 and 3 will receive miniature wooden dummy shotguns at Christmas when big brother gets his 20 gauge. I plan on letting them carry their "guns" afield with us when they go to begin learning the way to handle and carry a firearm.