For your wife, find a .22 pistol to start her out on. Not much recoil at all, and she'll be able to work on her stance, grip, and start working on issues like flinching. Get her out to a range with one for a few trips. She'll let you know when she's ready to try something bigger.
Lots of patience is needed though. If you have a highly qualified range instructor near you, it may work well to allow another person to coach her on the best ways to learn to shoot. We all think we know best...but if you want her to really come to love shooting, it may work best to allow an independent third party to be the coach.