The older two digit models (38, 42) usually have much better triggers than any of the three digit models (eg 642). The older revolvers are generally better fit and finished and consequently much smoother, ( to me at least) easier, trigger actions.
Even the two digit models can be vastly improved by a good gunsmith.
Find one (a good gunsmith) and get the trigger fixed.
This is not a do it yourself project unless you are a good gunsmith: forget the idea of buying drop in parts. This really is much too important to learn by fiddling with your own revolver - you wouldn't try to learn how to fix your brakes by practicing on the car you take the kids to school in.
Since you intend to carry in a purse ( much easier to carry than in a pocket or on a belt) an all steel M 49 or M40 would also be options.
Most j frames benefit by skilled trigger work. The two digit models (36, 38, 49, 40, 42) are much better, before and after skilled trigger work, than the three digit models in my experience.
I find the Ruger revolvers functional but clunky. S&W revolvers (older j frames in this instance) are elegant in comparison.
Unless you are planning on a very good (eg 40+hour) training program expending about 500 rounds - such as the Gunsite course, I would not recommend a pistol (semi auto handgun). Although there are lots of pistols marketed in the self defense industry, a revolver is much easier, and better, from a safety standpoint than a pistol.
Just my opinion, of course.
