Does she have much shooting experience? Generally speaking, folks who haven't shot much and who don't intend to shoot much are probably a little better off with a revolver than a semi-auto. They're easier to learn to shoot, and you don't have to worry about teaching jam-clearing drills. Check out something like the Ruger SP-101 in .357 Mag or .327 Mag. With the .357, she can shoot some nice mild .38 Special target loads for practice.

If you insist on a semi-auto, the 9mm is little more tame than the .357 Sig. The Glock will work. You might want to also check out the Springfield Armory XD. I like the grip angle a little better...

http://www.springfield-armory.com/xd.php