I faced the question when I convinced my wife to get her ccw. I was smart enough to let her choose her own firearm. Went to the gun store and "tried a number of sidearms on". I wanted her to get a G19 but she chose a Walther PP something or other. It fit her really well and pointed well. After shooting a few hundred rounds, she realized that although the ergonomics were good, the trigger was difficult along with some other aspects of operating the firearm.
We ended up with a G19 for her. Points well for her, simple and RELIABLE.
For me, Glocks just don't point well. I also like having an external safety for the way I carry and use a firearm so I own a few, but don't carry a Glock.
I would recommend two guns in particular to look at.
1. KAHR P9/CW9. You can find good used for $350 range normally. Both are super comfortable and very accurate pistols with one of the best triggers around. I would not recommend the smaller version of the KAHR due to small size and handling issues. I have had a KAHR P9 since they came out years ago and it is my go to gun many times.
We looked at the Kahrs for my wife. I don't know much about them other than what I've read. I do know they do provide an option of a nice small, slim sidearm.
Best option is to get to the range with a couple different sidearms and have both of you shoot. I always direct people who aren't semi-auto experienced to Glocks. Simple, point and shoot and RELIABLE. G19s are nice sidearms that can be used as a bedstand gun as well with larger mags for even more capacity. Would be ideal if both of you carried the same design to keep things simple.
As to cost, I have seen many lightly used Glocks for that mid $400s.
Finally, get good holsters. Don't be satisfied with something that justs works. Find holsters or carry means that work well for you and your wife. I have a few holsters I use that work well for me. My wife generally doesn't "carry" her sidearm. Wen she does take her sidearm, it is generally on a road trip. In that instance, she uses a custom made fanny pack I had made for her so she can keep the gun in a holster and be able to throw it around her hips when she stops while traveling with the kids.
