So I'm thinking of purchasing a gun for my parents to keep around the house for self defense. My mother has MS, and as such, can't take huge amounts of recoil without injuring herself. Obviously, I'd want to purchase them a gun that she could at least shoot from time to time to stay practiced. Any recommendations on what caliber to go with? I know my 9mm would be WAY too much for her. Obviously .22lr isn't going to do nearly enough to someone to be effective as self defense, but that's the kinda recoil I'd like to find.