Another vote for a full size 22LR
I went through the same type of thing with my wife.
We shopped for proper defense caliber autos. She settled on a Hi-Power in 9mm. Single action trigger is pretty easy to master. She can barely rack the slide though. If she uses the right technique, she gets it, if not, she doesn't. Not exactly confidence inspiring.
I reasoned that maybe since it is a single action gun, she can just leave it cocked & locked; then she won't have to rack it. But occasionally, she limp-wrists and jams it. One has to be able to rack the slide then.
What it came down to is that if she practices, she does well, and if not, she doesn't.
The reality is that she doesn't practice, but can ALWAYS shoot a .22 well. She has no problem racking the bolt/slide. She is accurate and confident. So she decided to get her own 22. (she thinks my Ruger Mk. II Target model is too heavy) So she got a Buck Mark. She loves it and shoots it well, even without practicing more than a couple times a year.
In short, I would feel like she'd do a better job defending herself with this 22 and good ammo than a 9mm or my own SP-101. (she hates revolvers; says they're "Old Man's Guns")
Perhaps more importantly, she
enjoys going shooting with it. When she's really in the mood, she gets going with the Buck Mark, then feels confident enough to try a centerfire again.
So the key is to get her a 22 of her choice, so she has something she really likes. (I've not yet met a woman who doesn't like shooting 22s) Get her to come shooting more often. If she enjoys it enough, she will come more often and may eventually build up to bigger guns. She will get accustomed to the noise at the range, and to some amount of recoil.
If she doesn't enjoy it enough to come more, at least she will have one gun that she is competent with. Oh, and you will also have access to it as well.
Here's the only pic I have of her Buck Mark. I highly recommend getting one with the "Contour" grip. It is much nicer than the old style one.
As it so happens, my Mk. II is directly opposite it. The red dot makes it easy to hit with, but also heavy, bulky, and not sexy any more.
Her Hi-Power is right below her Buck Mark.
She has shot the Bersa 380 on the bottom too, and felt that it kicks too much. The Hi-Power weighs so much more and has the locked breech design that does a better job of absorbing recoil.