The trick to easy slide manipulation is not to try to pull it back. Instead, hold the gun close to the body and grasp the slide with the support hand, but with the hand oriented more to the rear of the gun, kind of with the muzzle pointed out from under the wrist if you can picture what I'm saying. Then, use the strong hand (the one holding the gun by the grip/frame) to push the gun away from the body while holding the slide still.
Much easier to push away from the body than to pull toward it.
Don't discount the PT-22 if she handles it well. There are few, if any, bad guys that would run or otherwise cease to be a threat when countered with a centerfire defense that would stay and soldier on with their attack against a well-executed rimfire defense. Assuming a non-risky lifestyle, I'd bet your wife could live ten lifetimes without meeting any of them.
I own the Bersa Thunder 380, and it is indeed a great, sturdy, and reliable defensive platform.
Oh, and visit here:
www.corneredcat.com, the premiere ladies' firearms site. See the section for men as well.
Edit: I see from another thread you are 77 years of age, and she is 60. It doesn't sound like you're going to be at risk for a dangerous lifestyle, and firearms may not become a pastime for you. However, kudos for wanting to take responsibility for the safety of your spouse and yourself. As I said, if she's doing well with the Taurus, she should be fine for quite some time. More than a fair share of bad guys have been driven off or put into the ground with "Granny's little .22". Training should be geared toward situational awareness and rapid response as much as, if not more than, actual marksmanship.