good HD options for a small-statured single mother?
I want to add something to my suggestion. Even if you could find a place to keep a long gun that's convenient to reach and away from the kiddos, I still think its a bad idea. Rifles, shotguns, and pistol caliber carbines have one thing in common:
They require two hands to operate. I'm well aware of the fact that they can all be fired with one hand, but I'm trying to think like a small woman with kids. In addition, this is a technique that would have to be taught. If she needs to corral the kids, try doing that while keeping a long gun ready to use. Having a free hand is going to be very important in her situation. I'm still going with a 9mm semi-auto pistol for her.
I would also strongly recommend at least some level of training as well, but I understand it might be tough in her situation.