Well I've always said a 686 4.2". Mainly cuz I'm a revolver guy. It's deadly accurate too.
I just recently got my first polymer pistol a walther PPQ. I'm thinking that would be a good choice too. It's also surprisingly very accurate. First two shots I took with that pistol were touching. Nearly dropped it I was so surprised. Lol.
I've often wondered about the keltec pmr-30. It's very lightweight. I know it's only .22 magnum. But if mag restrictions were lifted. It holds 30 rounds of .22 mag. Just the shear amount of shots you could take would have to make an assailant think twice. Thinking it would be perfect for a woman for self defense. Light, low recoil and lots of chances to hit target