Since you're looking for a sub-compact, a revolver might NOT be a good choice for a woman, especially a very small hammerless chiefs special type revolver. Why? Well, she might not have the hand strength to pull a double-action revolver trigger, and in a crisis might not have the presence of mind or the time to manually cock the hammer for each shot (if there's a hammer to cock at all). Second, if she can just barely manage to pull the DA trigger, it'll probably throw her shots off so much that she'll be lucky to hit anything past a few yards. I don't know her, but I know my wife would struggle to pull a DA revolver trigger, and she's a bigger woman than your's is. My wife is also very recoil sensitive and doesn't handle anything bigger than a 9mm well at all. Your wife may be the same way, and if she is and you get her a pistol that kicks beyond her comfort zone, she won't like it, and if she doesn't like it, she won't shoot it. Women, in my experience, don't have the bravado about shooting uncomfortably hard kicking rounds that men do. Unfortunatly, unless you've shot with her before and know what she can handle, you won't know until she tries, but it'd be a shame to buy her a .357Sig or a .40S&W sub-compact that she refuses to shoot. Might even turn her off to shooting altogether.

My recommendation would be to take her out to a range where you can rent various pistols for her to try if you can. If not, take her shopping with you and have her handle several guns and see which one she likes best. But I'd probably suggest you start with either a Springfield XD or a Glock, either in 9mm Parabellum. I, personally, like the XD better than all the Glocks I've owned because the stock trigger is better and the XD has a more comfortable and natural grip angle. The reason I suggest the XD or Glock is because they are rugged, reliable, and are SIMPLE to operate when you are awakened from a dead sleep by the sound of an intruder coming down the hallway. As long as they are locked and loaded, they are pure point-n-click pistols. No manual safeties to forget to take off when the bad guy is three steps away and coming fast. Because I have (very intrepid, who can climb anything) kids, I keep mine unloaded and out of reach, but with the slide locked back and a loaded magazine close by, and my wife knows how to quickly load it if necessary.

But if you're in doubt, get her a 9mm. With the very good defensive ammo available today it'll do the job just fine. If a good hit (or two, as a good rule of thumb is if it's worth shooting, it's worth shooting twice!) from a 9mm with good ammo won't stop an attacker, you don't need a bigger pistol, you need a rifle. I like Federal Hydra-Shoks, but there are plenty of other selections out there of good defensive ammo. The most important thing is to run a few boxes of whatever ammo you choose thru it to make sure it'll cycle reliably (some guns don't like certain hollow points). My XD and the Glocks I've had are and were all 100% reliable with Hydra-Shoks.

Mike