Women and guns are highly over rated projects unless they handle, shoot, and pick themselves.
Noteworthy opinions I hold:
1). I have a S&W M&P340 .357, a 351C .22RFM, and a 43 .22LR. The 351C and 43 have pathetically heavy triggers that make them a bear to shoot. The 340 is wonderful. The difference is the heavier hammer strike needed for the .22s. Avoid them.
2). Caliber for caliber, the Ruger LCRs are far better values and far easier to shoot more accurately. They have a smoother lighter by 2# trigger pull and are a relative joy.
2a). Short LCR .38 shooting review post: http://www.ar15.com/forums/t_5_32/158221_LCR__38_Special__P_Review.html
3). For the .22s, in a revolver, use Hornady's Critical Defense .22RFM. In. .22LR, CCI Velocitor with the dimple front end. Feeds and goes flat but hangs together.
4). Have a Ruger SR22P which is a plain joy to shoot and 100% reliable with CCI products.
4a). SR22P set up test post: http://www.ar15.com/forums/t_5_4/148288_Beginner_Level_Set_Up_Of_A_New_Pistol.html
5). Have a Walther PP .22LR which is wonderfully accurate, heavy to carry, and has a horrible trigger reset with no feel.
6). Have a Beretta M21 .22LR which is small, a little thick, works 100% with CCI MiniMag and Blazer, and is accurate for its size. The tip up barrel avoids all the slide issues and makes clearing it easy. The spring system on each side eventually cracks the nylon grips. But not the wood ones which are a tad thicker. Keep to the "standard" .22LR high velocity ammo since the hyper velocity stuff works the slide too vigorously. Very good choice in general.
7). But for a really class little .22LR, find a M34 or 63 with a 2" barrel. The steel frame doesn't need extra power hammer springs and they always work to the limit of your .22LR ammo. Most expensive option mentioned here.
8). But if your "buddies" wife really wants a gun, recommend a SR22P so that she can learn to shoot or any K frame Smith .22LR. When she can shoot, recommend a Glock 19 or a Smith M10 2" Round Butt .38 Special. Skip the little hard to shoot (for most women) guns and get (sorry recommend) something useful and powerful enough to work. (Unless his girlfriend is like my wife. More than .22LR or .22RFM kicks too much.)
9). One and done. Really though, a S&W Shield 9mm is as good as it gets for a person who really wants a gun. With the Hornady 100 grain 9mm Pink Box Lite ammo, if that is too much recoil, they don't want a gun.
10). Avoid any thing as small as the M21 in centerfire of any caliber unless you want to turn them off to shooting entirely. This is the silly BodyGuard .380, Kahrs of most varieties, any of the .380/9mm mini/micro/lightweight and so ons. Few people ever learn to shoot them well enough for them to be useful.
11). I would admit a Beretta Tomcat in .32acp might just, might just have some utility if it worked dependably. Never shot one or tried one.
12). Skip Taurus guns unless you want headaches about the time you think it is broken in. If you want something that looks like a Beretta, buy one. If you want something that looks like a S&W, buy one.
13). I know for a fact that that little easy to use Beretta M21 beats squeaking, "help me, help me", while some evil doer has his way.
14). Easy comparison of Shield size single stack 9mm and Beretta M21 .22LR. Twice the weight and a lot more size. Same base width in the two holsters shows the relative size. Add 3/8" if you use the 8 shot Shield magazine that extends the grip.