first, as lastly SHE has to be good and comfortable with it (sorry, but I'm one of the biggest cheerleaders of 'let her choose' on her, would hate to be called a hypocrite)
For me, it was a P32, adequate round (and in all things here, there's a trade off)
only thing smaller I've found is some of the OLD .25's, and they weigh about half again unloaded. FOR a pocket gun, it's smaller than my wallet, lighter than my wallet, and hold 8 rounds.
Compare it to the next up, the P3AT, Ruger's knockoff the LCP, and that side.
VERY snappy, all the P32's compromise faults magnified for a larger round...
Sights suck on a P32, HOWEVER, I can put the mag quickly in a pie tin at 15 yards, so they work.
As for the others, Walthers, price and feel put me off of them, for a pocket gun, no, others got passed over due to size, weight when compared to the P32.
After I got the P32, I was happy, and that was that (and remember they can have teething problems, but its a sub 300 gun, well made, not 'Finely' made)
When it comes to guns, much is dictated by how you carry, I'm not high risk, I'm happy to have a gun, and accept that, drawing from a pants pocket is SLOW... and by pocket carry, I limit the practical size.
OK, OWB (sorry but, most people don't noice open carry, so Ive gone to the idea, of why bother UNLES it's to comply with state law) easier for any size to be carried, deep cover, you have ALL sorts of carry systems, Hell you can get a neck lanyard for a P32 or even a NAA mini-mag revolver.
Point is, there's just about someway to carry anything you like
limiting factors are YOU, what you want to carry, how you want to carry it, what you want to carry it in. You can go with a $30 leather superfly poctet holster, a $3 uncle Mike's, or me, a $9 blackhawk pocket holster. She can get a Bang Bra (think that's it, tucks the gun up in/under her breasts) a belly band or a drop leg, it's what she is comfortable and WILLING to carry.
SO, it's not just the gun, its an entire system, ask any of the old timers, they have guns and boxes of holsters that have rotated into use and OUT as they found what they like and works for them. The gun is one piece, for her, she has to decide, just remember, in LITTLE, .380 isn't tame, but at the same time, she may feel more comfortable with a 1911 on her hip.... Or a Baby
Bronwing in her cleavage.
EDIT: Sorry, JUDGE BASHING COMMENCE----> Not a SD gun, sorry, but, it's a 'toy' not a serious working firearm, there are MUCH better guns that do what it does, your job is to keep her from junk, it's fine for snakes and such, and offers versility, however, for CCW, there are better, just as you wouldn't put an Airweight .357 snubby loaded with fullhouse loads in a first time shooters hands, neither should you let her buy crap.