For reference, my wife chose a Glock 19 (9mm) for her carry gun, and shoots it in IDPA competition to stay effective with it. She fired mine and liked it so much that she knew there wouldn't be anything better for her carry gun. She likes the simplicity and reliability of Glock - she's intimidated by my USP45f - too many buttons/levers...
She believes that the Glock design makes for an excellent first gun because it offers certain traits that are user-friendly: 1) no safety - you HAVE to be careful with it *always* and it offers no 'safety' to quell you into a false sense of security, 2) quick into action when you need it, 3) controllable recoil (she's 5'2", 135lbs, fairly slight build), 4) easy to clean, field strip and clear jams, and 5) utter reliability.
If she can't trust it, she doesn't want it.
I was glad she chose for herself, however. Don't think that you can 'steer' her toward what you think is best - let her do the shopping and choose the one that makes her feel confident in it's use. She's going to be the one carrying it, remember, not you!
Good luck, and encourage her - many wives won't touch guns. Sure feel sorry for those guys,