Private schools have long played a crucial role in male elite formation but their importance to women's trajectories is less clear. In this paper, we explore the relationship between girls' private schools and elite recruitment in Britain over the past 120 years -- drawing on the historical database of "Who's Who," a unique catalogue of the elite. We find that alumni of elite girls schools have been around 20 times more likely than other women to reach elite positions. They are also more likely to follow particular channels of elite recruitment, via the universities of Oxford and Cambridge, private members clubs and elite spouses. Yet such schools have also consistently been less propulsive than their male-only counterparts. We argue this is rooted in the ambivalent aims of girls elite education, where there has been a longstanding tension between promoting academic achievement and upholding traditional processes of gendered social reproduction.