The Conqueror's Child

From the front flap of the Tor first edition: "The Fems were slaves of the men in the Holdfast, until Alldera Conqueror led a band of rebels to overthrow the rule of men and build a world where women rule. Now Sorrel, Alldera's blood daughter, is coming over the hills from the camps of the Riding Women to join her mother, to claim a mother's attention and love. She brings with her a young boy she has adopted. She is desperately protective of this child; she has to be. In the world she left behind, men are aliens - and in the world her mother conquered, they are slaves."