Re: home defense caliber and rev. or semi-auto ?
We always need to ask how qualified someone is who may getting a gun. Male or Female either way, if the individual is not qualified that changes the answer from one who is.
Panty 6 was and is still a natural shooter. She just pickes up whatever and hits bullseyes all damn day and for some reason has no bad habits. I have given her very little pointers over the years because of this.
My mom on the other hand, was not a very good shooter, and her little Berretta Tom Cat(.32 ACP) after she got bored with it, sat in a closet for years until I recovered it upon her death.
My Brother and I were both within 911, real 911 distance from her so we could actually respond in time to stop something bad from happening back in the day.
If your mom is fine with a handgun. take her to a range that rents guns, adn let her pick what she wants to shoot. Advise her on the calibers and point her toward oh, 9mm, .40, or even .45, and the .38's and .357's. Panty 6 used to hate .357 MAgs, but last time we went and shot handguns, she was all over the Colt Trooper and the full house loads. Her favorite is still the .45 though, because 'it has a really authoratative BOOM!' Yeah, most women who haven't shot regualr basis feel so empowered when they get to shooting all the time. Get mom out to the range and let her do some damage on paper and metal.