I bought my mom and my sister consecutive Kahr MK9s for Christmas. They loved them. I replaced the standard grips with nice looking (and exceedingly comfortable) wood grips. I chose the model because it was easy to use (nothing to manipulate but a triger, slide and mag release), compact, relatively powerful but still light-recoiling and cheap to shoot. I got pinky extensions for the short mags so they could always get a full grip. They did not ask for these guns (they never would) but are very happy to have them. They enthusiastically request that I take them to the range every time I am home.
That said, I have known my mom and sister for a very long time and have been shooting with them on numerous occasions. I am also a highly competent instructor and was able to familiarize and coach them without making them uncomfortable. I had been gun shopping with my mom before and knew that she like a little bit of heft, preferred an auto to a revolver, and wanted something that would fill her hand.
I guess what I am trying to say is that in my situation, I don't think buying guns for them was a bad decision. They are realtively experienced shooters whose tastes I am familiar with, and I am an experienced gun-buyer who has trigger time on a very large variety of guns. In you case, I would get her to a gun shop with a big selection and let her try some on for size. If possible, get her to a range with a similar weapon and let her compare some side-by-side. Then, based on what you know about her, make a selection.