A .45 probably is a lot of gun for most women. Some women of my acquaintance are even a bit overwhelmed with the 9mm. I’d be somewhat concerned about recoil with a shotgun as well. Maybe the best advice is for pepsi_junkie
to take his wife to the range and try some rental guns to see what she’s comfortable with.
If you live in a CCW state and have a permit you have “about town” and “home defense” considerations. About town you have a small gun with the best performance for you. I have CCW and my choice is a pocket carry 40 cal Semi-auto or in winter a 1911 high capacity 45ACP. At home you can use the CCW to fight your way to a better gun. Myself, I have a Mossberg 500 12ga (sometimes slugs, sometimes buckshot depending on bear threat). Thinking of pulling the Springfield Armory MiA Match grade 308 out of the safe due to greater magazine capacity. If someone broke in the dogs would be all over them. I would need to make a precision shot to avoid hurting my dogs. I wish the worst on crimminals so they would get what they deserve.