I own a 22/45 and my wife recently started to shoot with me. I decided to buy a second gun, it will not be my last, and it will be a 9mm. If the 9mm I buy can also work for my wife great, if not we will buy two so she can pick one that works best for her.

So the process is underway to try as many 9mm as we can to build a short list and then work through the short list in a more extensive manner.
Last week my wife and I shot a Springfield 1911-A1 and a Glock 19. While both were fine we both liked the 1911 a bit more.
Today I went solo to Reeds in Santa Clara and rented a Glock 17 and a Beretta PX4 Storm. The secondary goal was to work on mechanics. We think we are both limp wristing.
Set up:
100 rounds
5 round magazines
40 rounds through the Glock
60 rounds through the Beretta
Limp wrist fix results: 1 Failure to Eject
Observations:
I enjoyed shooting both guns. Shot placement, I need a lot of work, was similar. The Beretta felt the best in my hand. Having shot two Glocks the magazine release gives me some trouble. I need to find the trick for smooth release. It seemed to me the Beretta had slightly less muzzle rise but I really need to shoot both more to reach a conclusion. I like the appearance of the Berretta over the Glock.
Conclusion I would be happy purchasing either gun from the function perspective but would select the Beretta from the appearance perspective. Current order of selection if I were to buy today:
Beretta
Glock 17
Springfield 1911-A1
Glock 19