John Wesley on 2 Samuel 20:21

Ephraim - Probably mount Ephraim was a place in Benjamin so called, either because it was upon the borders of Ephraim or for some notable action or event of the Ephraimites in that place. His head - Which she undertook, because she knew the present temper of the citizens, and soldiers too. And it is not unlikely, that this woman might be a governness in that city. For though this office was commonly performed by men; yet women were sometimes employed in the government: as we see in Deborah, who judged Israel, Judg 4:4.