I had the same question a few months ago and this forum helped me find an appropriate gun.
With that being said, I don't think that many people understand what it's like to be a truly petite female in the gun market. I am almost exactly the same size as your wife and have tiny hands (I wear a size 4 shoe, if that's any indication). Most guns are too large for me to shoot, including the XD9 subcompact and full size 1911s.
You need to look for a gun with a narrow grip AND a short distance between the backstop and the trigger. Not many guns offer that.
I ended up purchasing a Springfield 1911 EMP because that's the only gun I could find that was small enough for me to handle, but heavy enough to absorb recoil. I LOVE it! I can rack the slide much more easily than any other gun I've tried and I can reach the trigger just fine. Recoil is mild, accuracy is high. And it's a good-looking gun, which helps. It's expensive, though.
Size-wise, I also liked some of the Kahrs, like the T9.