No idea of the velocity, if your wife's comfort/ability is a factor and she can shoot that combination well, don't fix what isn't broken. If she is willing to carry, I'd say it's time to hunt for another K frame for her, too. (K frames have one more round than the J frame, and are ergonomically easier to shoot well.)
I happen to think a round butt is far better than a square (I mean on the revolver;get your minds out of the gutter, you jerks
) and while a 3" barrel is harder to find and likely to cost more, is better than a 2". It is also just a bit more flexible, depending on carry method and her size (off body carry such as a purse is really sub-optimal and should be avoided if at all possible).