Input from my firearms enthusiast son. He’s young but he knows his stuff.
Since he has handgun experience and his wife will be using it also, I would recommend any of these.
Sig p229 9mm/40 S&W
Glock 19 9mm
Glock 23 40 S&W
Ruger SR9C 9mm
Beretta Px4 compact 9mm
Springfield XD compact 9mm/40 S&W
And mandatory for any home defense firearm, it has to have a flashlight mounted (Streamlight TlR-3 is the best option) because identifying your target is the most important thing.
Thank you...he’s leaning toward the Springfield XD in 40 SW. Good idea about the flashlight too.