Buzz,
Given that you don't know if she's going to stick with it, I'd opt for a 20ga auto to start with. A Beretta comes with all these shims to change drop and cast. But even a Remington can be altered very quickly for drop, cast and toe out/in. I just did a drastic change on a Rem 870 last night after a friend at the range gave me his "guest gun" and asked that I raise the comb by "bending" it, since he saw what I did with my sxs guns.
I ended up using a file and changed the simple head inletting. I raised the DAH by 1/2" and put a 1/4" of cast off in it. Took me about 2 hrs at the kitchen table with a flat file and some measuring stuff. I could have easily put some toe out in it. The good part about a Rem 870/1100 is that replacement stock is cheap and readily available. Another way to go would be to put an adjustable comb and buttplate on a shortened gun. Then she could "tune" it as she got more proficient. I think a lot of us have tuned our dimensions over the years and various guns.
With the autos, most have some limitations on how short they can be cut due to a spring housing in the butt. The 870 pump doesn't have this.
The guns I've seen small women have had grips that were small diameter and tight/close so the small hands could reach the trigger, the combs were very high, lots of toe out and cast off.
Last edited by Chuck H; 11/19/12 01:17 PM.