My great-grandfather Waddy (Thomson) Poindexter was the owner of two slaves when he and his family settled in Calloway County in 1833 and then moved to Carroll County, Missouri. According a family story, his daughter, my great-aunt Bithe, once aimed a shotgun at some bushwhackers who were trying to take the two (who were hidden under a bed). She was a big woman and threatened to blow the bushwhackers heads off. They cleared out.
The slaves were children according to an 1850 slave schedule.
I'd like to think, of course, that she was being protective of them as people but it was probably being protective of the family property (the slaves).