Aglass,
I agree HIGHLY with the advice to let her shoot one first, if at all possible. I got two Airweights for my wife & daughters--they loved the fit, feel and simplicity, until they fired the guns & the recoil, blast, flash, muzzle flip etc. were too much for them. Those guns are somewhat famous for their recoil, and even the 110g "Low Recoil" loads have a flash & muzzle flip that ruined practice for all of them.
My $.02 is to consider a steel-framed revolver, all else being equal. Heavier to carry, but easier to shoot in practice. My wife likes her Detective Special a lot and shoots it well. I used to have a Beretta 84 that I bought "for her," but the grip was too thick and the muzzle flip too unpleasant--not to mention the hand strength issues associated with racking the slide.
Bottom line: after years of guessing wrong, I let my wife choose both gun & load now. Best of luck finding an option that works for your wife! I'm getting my girls to shoot some again now, using .32 revolvers that fit their hand & don't hurt in recoil. It took my older daughter a while to steel herself even to pull the trigger on the .32, after the above-noted Airweight experience, but she quickly started to regain the form she had learned with .22s. Of course, more powerful is better, if your wife can handle it.