Shotgun extends out, easy for someone to grab. Self-defense experts recommend a revolver or semi-auto. I would recommend a S&W .357. Kick isn’t as heavy as a .44 or .45, and it will do the job. A revolver is ALWAYS ready to shoot, and you don’t have to work the slide or worry about it jamming.
Put a pistol grip on it, and learn to shoot from the hip.