My recommendation for a firearm for ANYONE:
"Purchase the largest caliber handgun with the biggest capacity, that you will feel comfortable carrying on a daily basis."
Cap has it right. You can do a lot of things, but if it doesn't feel right to her she will not carry it consistently. SWMBO hated every firearm I had until she picked up a Kimber Ultra .45 ACP and she fell in love.The best answer is: take her to the gun store, have them show her what they have and have her pick them up and get a feel for them. Once she finds something that fits her hand to her satisfaction she will need to fire that caliber to see if she is comfortable with the recoil. In short, every time someone asks these kinds of questions, you'll get everyone's favorite gun for an answer. Choosing a weapon is a very personal undertaking. Let her decide, because she's the one who's going to be using it.
This explains why you are an instructor. You see what I mean, Phillip -- every time someone posts a thread asking for recommendations you'll get a list a mile long of calibers and particular firearms. I use a Browning Hi-Power for concealed, for instance, but that does not mean that I will recommend that one. It was a PERSONAL CHOICE, as is the selection of any firearm for any given person, so hopefully before we get lists of "best calibers," "best semiautomatic," etc., Norman J will just take your advice.