I understand the issue of small hands. Have you looked into a Glock 19 with a grip reduction ?
Robar & Bowie Tactical do very good work.
With all due respect, why waste money getting a Glock with a slimmer grip when you can buy a handgun that already has it? I also think the SR9 and M&P far surpass Glock in terms of grip slimmness, grip angle, sights, and features from the factory. If I were buying a gun for a younger shooter, I think I would prefer it to have a loaded chamber indicator, which the Glock lacks and the others have. The SR9 also has a safety in case the OP wants her to have that.
And I'm not sure what I'm missing here but I think both the SR9 and M&P9 can hold 17 rounds. I know my SR9 can hold 17 rounds and I'm pretty sure I've fired an M&P that fits 17 rounds. But, the SR9 is more affordable and I think it would be perfect for you since it has a thumb safety and a loaded chamber indicator. It also has a magazine disconnect safety but I would suggest removing it once you get it. Luckily the process of doing that isn't all that difficult.
Here is a review I did on my SR9c, which is simply the compact version of the full sized SR9. Hopefully I touch on all the points you want to hear. http://www.youtube.com/watch?v=l5GwpHH-pzI&feature=plcp
EDIT: Thanks for backing me up TigerOTH. I also didn't consider the lower 22WM velocities out of a short barrel. That explains the PMR30 fireball I've seen before.
This post was edited on 10/3 at 10:16 pm