Telling women to get a revolver these days is a bad idea, especially for older women. Revolvers have neither the recoil mitigation nor the ammo capacity needed for modern self defense engagements. Rate and volume of fire is even more important these days.
A J frame, that is.
A .38 Spl with 90 or 110 gr Hornady Critical Defense or even 148 gr HBWC have mild recoil.
I would advise a semi, too, but maybe that's all they have or are comfortable with it.
Many women, especially many older women, have difficulty racking the slide on a compact 9mm. Not all but many. Some of the little pistols have tough springs in them.
Whatever works for an individual, though. That’s what’s important.
However there are several reasons I don't recommend pistols and do recommend small, hammerless revolvers in some circumstances.
(1) No safety
(2) No magazine
(3) No magazine disconnect safety
(4) Entirely one hand retrieval and use, if necessary
(5) Lower likelyhood of opponent getting a hand on the weapon
(6) Ease of training and recall of training.
I personally use a 10MM Glock for which I handload combat ammunition.