:cb2: If you are getting something for your wife to use, the most important thing is make sure your wife can use it. I used to sell guns, and far too often I saw men comming in to buy their wives a gun, but they looked at something they wanted their wives to have, rather than a gun the wife could actually use.
Before you buy your wife an automatic, make sure she can operate the slide first. It's more than just strength—it's technique as well. Just because YOU can do it, and it seems easy to YOU, don't assume your wife will able to do so if it jams in an emergency situation. (Do you even want her to carry a gun that can jam in an emergency situation?) Have her try it in the store. If she can't operate the slide, don't get it thinking she can learn how later, because 99% of the time she won't. Also, is the grip comfortable? Some automatics are just too big for some women to handle well.
Practice shooting at the range: Can she load the magazine easily? Pop it in and make it seat properly? Operate the slide? Clear a jam? Are the controls (safety, magazine release, slide release) easy for her to operate? If any of this is hard, a woman isn't going to do it.
Therefore, I'd suggest a revolver. Simple and easy to load. Fewer working parts. If it ever goes "click" instead of "bang" all she has to do is pull the trigger again. Very reliable. The grips are smaller and usually more comfortable. In this world where everybody seems to be in an automatic craze, you can usually pick up a good used S&W, or Ruger revolver at a very good price. (Just don't buy anything that starts with a "T"!) A .38 is great, but don't think that is all a woman can handle. Paxton Quigley ran a handgun training school for women. (Don't know if she still does.) She said the two guns her students liked to shoot the most were the 1911 (.45 ACP) and the Ruger GP100 (.357 mag.). My wife is a medium sized woman and carries a .357. Her favorite gun to shoot is my Glock 21 (a BIG .45 ACP). Women do not focus on recoil. My wife doesn't even know what that is. She was trained to focus on the front sight, and does. Men (most anyway) are focusing on what is about to happen.
If you do go with an automatic, please don't get anything smaller than a 380 for personal protection. And if, for some reason you do go smaller, get the .22 rather than the .25. The .25 is sooooo under-powered. I'd rather put my faith in a rock.
Good luck. I know you're getting a ton of advise, but then, that's what this forum is for. There are a lot of knowledgable shooters here. I'm always learning something new. You've come to the right place!