Was watching a episode of NRA and the subject was on the best firearm for a woman, I think 15 different firearms from revolver to semi-auto were tested by women. They all hated the revolver. In addition one must remember the smaller the weapon the lighter the weapon the more the recoil. But it is their choice, as the previous poster said. Whatever fits their hand and they are comfortable with should be left up to them. The only problem with a semi-auto is that the person must be capable of racking the slide. The consensus of the majority of women was for a .380, but do not remember the manufacture.
My wife has a hard problem racking the slide of my 1911 45acp but she loves the weapon, however that would not be a problem with a home defense weapon since it is always loaded with one in the chamber However she also took my Glock 43 for her carry weapon. Oh well have to keep the little lady happy and a good excuse to purchase another gun