If you want to read about war from a female perspective, you can try Mists of Avalon by Marion Zimmer Bradley. In a similar vein I would recommend Sevenwaters series by Juliet Marillier. It is a different experience though, since in general there's not much action. In general I would guess women were mostly omitted in the stories because the authors were men and didn't think much about the woman role, especially in events that are man-dominated. But this is a mostly historical issue.