I think if you push to hard, she may "give in" for lack of a better term only to make you happy, not because SHE wants to get her own gun.
Slow and steady wins the race, while she's dropping hints, just having a gun isn't enough, she needs the will to use such a tool, if she lacks the will, or doesn't fully grasp what it means to have a gun for self defense, she may be better off with OC spray. Work on her mindset first.
Also, don't discount the autos. When it does come time for her to get her own gun, let her choose, find a shop with range that has rental guns and let her try as many as possible. While a lot of women love J-K frame revolvers, they don't fit everybody. Choosing a firearm is a very personal thing. Everyones likes and dislikes are are different.
While your .40 may be to sharp in the recoil dept. (I don't like .40s for this reason) there's no reason to exclude 9mm and .45 autos from the list. My itty-bitty wife favors the .45ACP. in a 4" all steel 1911.
You may find some of these links helpful.
Member PAX's website: Cornered Cat
And my wife's (Limatunes) Website