Good advice.
I’ve carried both the slim, lightweight S&W 640 which handles .38 and .357, and also the Ruger SP101 which is a touch bigger and heavier but is a dandy revolver as well.
With both these models your lady can step up to the .357 if she finds she wants a little more punch.
I like the little revolvers which always go pow when you pull the trigger and damn seldom do if you don’t.
You beat me to the punch.
Hammerless - can be fired from inside a coat pocket (if need be) without external moving parts to snag on things.
Reliably eats everything from milquetoast light .38s to hot .357s.
Downside - Only 5 rounds instantly available vs. 7,10,13,17 with the semi-autos.