If your wife's hands are small, the problems the 92 could pose probably won't be with the weight of the trigger pull. I'd imagine her hand strength probably isn't bad, toting newborns around all day. The reach is probably going to be the issue, especially the DA reach. The 92 has a big grip. A long reach can force the shooter to rotate the gun, muzzle to the outside, relative to the shooting hand in order to engage the trigger. This tends to pull shots, and amplify perceived recoil.
She should pick out her own gun, when you buy the next. It should fit her hands, so she can get the pad or first joint of her trigger finger on the trigger while keeping the gun aligned with the long bones of her forearm. This will help with trigger control, sight alignment, and recoil control.
Not sure where the nearest range that has rental guns is, relative to your location, but if possible, it's always good to let people try a variety to find out what fits best, and what works best for them. If it's painful to shoot, they generally won't put in the practice time.
Expense is another factor. A .22LR, similar in operation and feel to the centerfire primary, can be a very good idea. So can conversion kits (the Kadet for the CZ75, for example), which let you practice with the same frame and trigger, by changing out the slide, barrel, magazine, and recoil spring. Conversion kits run in the $300 ballpark in many cases, so they are in the same price range as many regular .22 pistols, but I actually prefer the conversions on guns for which they are available. (Using the same grip and trigger really does help.)
Last edited by MLeake; January 18, 2012 at 10:50 AM.
Reason: Removing argument, moving it to PM where it belongs, going into "nice" mode