My girlfriend has been home for about 9 weeks recovering from cancer surgery and chemo. I was very worried about her physical state and her inability to defend herself from attack. She is a shooter and I asked her which pistol she wanted set up for her and she picked the Springfield Loaded 1911 in .45ACP. I loaded it, cocked and locked it for her, and put it in the gun safe that way. She is very competent with this pistol and i felt good about her choice. Her first line of defense in her 2 dogs, a purebred German Shephard and a lab mix. Both are extremely loyal and very protective of her.
My choices for a woman for protection would be first a good dog, if she is not a shooter. Second, work with her on being comfortable with a gun. Practice, practice, practice, until it is second nature.
The dog is auttomatic, the gun is reactionary and depends on human intervention. People's reactions are different depending on mindset. The most important thing about having a gun for self defense is having your mind made up to shoot if you need to. If there is any question of that, forget the gun and buy a second dog.