You are going to get a lot of opinions; here is mine:
1) All S&W J-Frame .38s are specialist weapons. It is possible to become effective with one, but there are two prerequisites that are not on your wife's horizon: first is developing serious pistol shooting skills, with .22s for openers and then with full size centerfires. Then (and only then) firing an awful lot of rounds with the J-Frame .38 doing serious defensive drills. So, yes, the revolvers you've identified are wrong for the lady you've described. She will find shooting them such an ordeal that she will give up trying. She might be better armed with an aluminum baseball bat.
2) My recommendation would be a Ruger SR-22 (if you can find one) and a whole bunch of .22 ammo (ditto). You start by giving your wife a chance to experience shooting that is fun. Then she gets good instruction and learns basic pistol marksmanship: sight picture, trigger break, stance. From there, expand to skills firing multiple shots, mag changes, clearance drills, carrying and drawing, and the like. So armed and skilled, your wife can do a mag dump against an aggressor with a far greater potential for a successful defense.