The heavier the gun, the less it will recoil. The gun's weight soaks up some of the recoil force.
If your wife has hand-strength issues, a long barrel will also help absorb recoil force. Maybe instead of a 2" snubbie, look into a 3" or even a 4" barrel.
Let her try before you buy. I believe that you will find trigger action to be a deciding factor, too. Make sure that she can handle a double-action trigger for at least five consecutive (dry-fire) shots. Some old Charter Arms revolvers had really light, nicely crisp trigger actions, so maybe the new ones do too.
Using two hands, it is possible to thumb-cock and fire single-action quickly and repeatedly, but it's a skill that has to be extensively and frequently practiced to make it "automatic" and usefully effective. It is not easy to do under pressure, when one is in danger. (The left thumb does the cocking, and the right index finger does the shooting.)