Keith B wrote:If you can rent a 9 and let her shoot it before buying, that would be your best bet. She may have an aversion to something with 'less' kick vs. 'no kick'. Renting or borrowing and trying out is a good method of not spending on a gun she may not like.
If that isn't an option, start her out on maybe a Ruger or Walther .22. They would be a good addition to your collection anyway. If she really gets into shooting, THEN move her up to the larger caliber handguns (.380, .38 or 9mm.) Pocket size guns like the KelTec P3AT or a small .38 revolver like a Taurus or S&W would also be a lighter option. But remember, the lighter the gun, the more they have a tendency to be 'snappy' with recoil.
Good luck!
If she liked the .22, buy her a .22. My personal suggestion would be a Browning Buckmark; they're inexpensive, accurate (highly adjustable sights), customizeable (Tactical Solutions has a lot of mods for most 22s) and fun. Even if she never progresses beyond it, she can have fun at the range for peanuts. The Camper can be found in the low $200 range, it's lightweight (though it does have a bull barrel), and it's almost recoilless, certainly compared to my 9mm. It's still loud, but it's a "crack", not a "bark" or "boom".
You can try her on a 9mm (it was my first gun and even for a novice shooter 9mm is very controllable), but definitely TRY her on one before you buy one just for her. Now if you want one for your own purposes, get it, and then she can try it. If she doesn't like it, it's still your gun. If she does, give it to her and buy another.