imported post
I'll comment only on the pistols I have actually fired.
Sig Sauer P250 - Nice modular design for caliber swaps from 1 serial number. I like that feature for shooting multiple calibers without having to have extra paperwork on file with WA DOL. It's also nice for a new shooter to learn with something (after starting with a .22 LR) like a 9x19 and then later stepping up to a .45ACP or .357 sig. (I wouldn't carry a 9mm or a .40 S&W but that's just my personal preference.) It fit my hands decently, was fairly accurate and functioned very reliably. The price is a little higher than some of its competitors, but if you're going to take advantage of the multiple caliber option the small extra initial cost saves you money in the long-run on 2 or more calibers from 1 platform. It's a nice system. The only downside is that it is a hammer-pistol but is Double Action Only. There's no option to carry cocked and locked.
Taurus 24/7 - Reliable, inexpensive, and fairly accurate. Some folks fall in love with the strange cushy grips and other folks can't stand them. I couldn't stand them. The trigger was sloppy and I missed having the ability to carry it cocked and locked. At least it was a DA/SA setup though. Holster availability isn't superb.
Taurus Millenium - It's the same DA/SA setup as the 24/7. I didn't care for it all that much. Basically the same comments for the 24/7 apply to the Millenium.
Beretta 92FS (Beretta M9 in my case, slightly different) - I hate this firearm. It's ridiculously heavy for its caliber. It has the worst safety/decock arrangement known to man. It's very easy for the user to decock and accidentally leave on safe. It's also easy to accidentally draw the firearm and have your thumb flick the safety on inadvertently if you carry decocked. I've seen this happen plenty of times at NRA Action Pistol events. I think this pistol accounts for more "squeeze - oops it's on safe" problems than any other pistol out there. I don't consider that design to lend itself well to daily carry at all. It's also relatively expensive. It IS reliable and accurate and there are a huge array of holsters available for it. (Many are oriented towards the military, however.) I could rant for hours about how much I hate this firearm but I won't.
H&K USP - I own and carry a USP Tactical (full-size) in .45 ACP. It is incredibly accurate. I think it's the most accurate pistol I've ever fired. They're expensive, but they are extremely reliable. I like the fact that you can carry them cocked and locked like a 1911 or you can use the decocker and carry decocked safely as well. The double-action pull is stiff and the single action pull is pleasantly light. Mine has zero overtravel, but that's because it's the Tactical with an adjustable stop. Trigger reset isn't as nice as a 1911 or any other SAO pistol is, but it's decent for a DA/SA setup. The biggest complaint is its size. Since I OC I didn't care, but even in the "compact" there's not much that's compact about a USP. They're blocky and the grips might be too large for a slightly built lady. Really the only downside is the size/grips/price. Holster availability is good, unless you have a Tactical model with the threaded barrel and taller front site, then things get tricky. The standard USP has plenty of holster offerings. Magazines are expensive.
Springfield XD - These are great little pistols. They're reliable, relatively accurate, inexpensive, and usually come with holsters, spare magazines, and magazine pouches from the factory. That's a nice touch. I'm not a huge fan of the striker fired systems; I'd really like to be able to carry cocked and locked, but these guys (along with Glocks) do the DAO striker fired stuff well. The other nice thing about them is if you get an XDm model, you get the ability to swap out different grips for different sized hands. This is a great option for ladies or men with smaller hands. They're also less blocky and more concealable than a USP.
I didn't see Glocks on the list. Don't overlook them, they make some great handguns too. Most of them are equivalent to the Springfield XD's but are a few steps up in terms of quality. (and price) Holster availability for a Glock is probably the best of any pistol.
I also didn't see any revolvers on the list at all. Don't overlook the S&W J-frames in .38 Special, .38 +P, or .357 Magnum. (With the Magnums you can carry spl or +P ammo instead of you desire) They're hyper-reliable and some of the airweight series are amazingly light. (I don't think I'd want to shoot 158gr .357mag loads from an airweight though... ouch)
EDIT: Also, the 1911 and its variants... If she can handle a H&K USP, then she can handle a 1911. The grip on a USP is slightly larger but the frame itself is nearly identical. (The difference is that the USP has the slide slightly farther back over the hand, rather than ending flush with the backstrap of the grip) All of the other angles and dimensions are nearly identical.
If the 1911 is uncomfortable for her to hold or shoot, odds are the H&K USP will be equally difficult for her.
Don't overlook the size/weight issues on the pistols. Concealability may not be an issue to her at the moment, but it's almost certain to become an issue at some point in time.