:cb2: I agree with williamlayton. I saw too many men come into my store wanting to get the "best" gun for their wives, but what they thought was best really wasn't. Many wanted to get automatics, but their wives couldn't work the slide. Also, many women wouldn't know what to do if the auto jammed, AND they don't really want to learn. They want something easy. That = revolver. Also the grip is smaller and better shaped for a woman's hand.
So let HER pick up and handle everything in the store if she has to, but let her decide what feels better in her hand. (Just don't let her even touch a Jennings, Lorcin, Davis, Taurus, etc.) If SHE likes it, she is more likely to practice with it, and learn to shoot it well.
That said, a .38, like you suggested, is usually a good choice, however, Paxton Quigley said that at her school the two favorite guns her students liked the best (all women) were the Ruger GP100, and the 1911. I know my wife loves her .357, and her favorite gun to shoot is my Glock 21 (.45 ACP), so don't think the ladies can't handle anything bigger than a .38 -- they'll surprise you!