Jack, let me help you.
I bought one for two reasons:
- My 11-year old daughter only likes to shoot .22s and she has tiny little hands. The MKIII and S&W 17 are to big and heavy for her so I got a P22.
- I wanted a small and light .22 for NRA Basic Pistol classes.
I can't speak on the "one type of ammo" thing because all I use are the Federal copper washed bulk packs and it likes that ammo just fine.
Bet she would really have fun with a Ruger Bearcat.
The alloy framed Bearcat is 1lb and the steel framed one is 1-1/2 lbs.
The Bearcat has a very small gripframe and should be just right for her.
If she can handle 2 lbs, the Browning Buckmark with the 4" slab sided barrel might work. I don't have a P22 to compare, but I don't think that the distance to the trigger is much, if any, greater.
You are right about size & weight for younger shooters though. It is a shame that there isn't more of a selection of quality guns.