You probably wouldn't walk into a shoe store, pick out a pair of shoes for your wife and expect her to love them -- and them to fit her well -- even though she'd never looked at them or tried them on before you plunked down your money.
If you wouldn't do that, you also shouldn't walk into a gun store, pick out a gun for your wife, and expect her to enjoy shooting it.
- take her with you to look at the possibilities.
- let her try the 'feel' of various guns in her hand.
- don't expect her favorites to be guns you would pick. She's picking a gun for herself, not to please you. If she picks one you like, that's gravy -- but don't expect it and especially, don't demand it.
- if she wants something lightweight, insist on renting one for her to shoot before you buy it. Light guns are fun to hold but plenty of women find them un-fun to shoot.
All that said. If you're looking for something for her to enjoy shooting, try the Ruger Mark II or the Beretta Neos -- both semi-autos in .22 caliber. Or look for a .22 revolver, maybe the newish snubby from S&W.
If she wants a home defense gun, maybe an L-frame .38/.357 revolver or a Glock 19 -- both very simple guns that are comfortable to shoot but pack a wallop on a receiving end.
If she might want to carry a gun, the traditional advice is to get a .38 snubby, but I'm not sure she wouldn't be better served by a semi-auto. I'm a little leery of the super-lightweight .38 snubbies, which seem to be what newbiew gravitate towards ... until they shoot one and find out what the kick is like. For semi-autos, try maybe a Glock 26, Kahr PM9, or subcompact XD9. If she's a lefty, take a look at HK's P2000 or P2000SK, both very good guns.
HTH.
pax