More and more, I come to respect the .22, a lot of people laugh it off. But's used to kill alligators on Swamp People, steers in slaughter houses, old men use them to kill burglars. If a woman prefers a .22, I might guide her toward a good .22 pistol. I don't have one, but I am surprised at what they do.
If the 22 rimfire is the final choice as to caliber, then I'd seriously suggest a revolver. The only auto that I have found to be reliable is the Ruger Standard model. Wheelguns are a lot more reliable than auto's, in my experience. I have a Walther PPK/s in 22 LR, and the reliability has been terrible.
Like I say, this has been my experience. YMMV.