RE: 5'9'' - 125lbs lady needs a 9mm?
I suggest you go to nearest gun store and handle all different models/brands and see which fits you best. The gun that has best natural fit will help you shoot best. A thought is possibly move up to .40s&w.
People with smaller hands pick kahr semiautos quite often. I might also suggest para ordnance in the smaller models (my favorite brand).