At some point, not long after she learns the basics of safe handling of firearms, will come a point where there is no substitute to arranging her to spend a half day or a full day with a good instructor. Not just someone who can teach her the range safety rules, but someone who can actual teach the techniques of how one uses a pistol correctly and effectively.
Since you are asking about 9mm gear, I would venture to assert it should be along the line of an instructor with ex-LEO-tac training, or a qualified instructor in IPSC etc.
I would consider that many times more important (and more fun) for a new shooter than finding the perfect gun.
After experiencing that training, one would also become more informed about what type / model of pistol to go after.
If I am providing that as an advice to my own family member. I would recommend a new shooter to take a cheap but functional pistol (e.g. whatever like Norinco 1911, Ruger SR9, Norinco Sig clone, etc etc) with a paid half/one day course, over an expensive pistol (e.g. a real Sig), any day.