Back when you could find the ammo, I would have recommended a revolver or semi-auto in .22lr (her preference, of course). With a good quality load, it could defend her home adequately. The practice ammo is (was) cheap, encouraging practice & helping her save for training. And a good .22lr handgun is just plain fun to shoot, encouraging more & deeper participation in shooting. I lean more toward revolvers mainly for ease of maintenance & price of speedloaders vs. magazines.
Besides.....as we all know, the .22lr is the "gateway caliber".....get them hooked on it first, then they'll start looking to get on the heavier stuff....
