My wife is also quite small just about 5'2" with a slight frame. A semi auto was problematic given the strength needed to rack the slide. A tip up Beretta would have solved that but she tried a S&W 34-1 .22 revolver that I had and liked it. The trigger pull was a bit stiff for her so I had a smith do an action job and I think it is ideal for her. She spent a day of familiarization firing at a range with instructors in an all female class and I believe that was also a good thing. Good luck with your wife finding the right gun for her.
