If she can't handle the recoil or the slides on those guns, a PF9 or LC9 makes no sense. Those guns will kick harder and the slides have less to grab onto with stiffer springs.
The Glock 21 is a very soft shooting gun compared to an LC9.
This exactly.
Can't fight physics.
The smaller and lighter a pistol is for any given round, the more recoil, perceived and/or actual.
The sub-compact 9mm pistols available today are great for concealed carry, but in my experience, aren't the most fun to shoot more than a couple of magazines through.
Definitely would suggest you stick with the .380 for her, as it is both easier to shoot and control, and has a lighter recoil spring, making slide manipulation easier. With modern defensive ammo, at the typical self defense encounter of just a few feet, .380 is nothing to scoff at. I have a Glock 42 with the Taran Tactical +2 extenders, giving me 9+1 rounds in a small, thin, lightweight, ultra-reliable easy to control package, that I still occasionally carry.
Do the bulk of her training on full size pistols, so as not to turn her off on shooting a heavier recoiling sub-compact, followed with enough shooting of whatever carry piece you decide on that she is comfortable with it.
