This study employs studies on gender and nationalism, and social movement theory, to understand how the activism and roles that the Egyptian Muslim Sisters have played in the Muslim Brotherhood movement have evolved throughout history, and in light of the changing political circumstances that followed the 2011 uprisings. In doing so, this study pays particular attention to women’s ideological and strategic assessments, the MB male leaders’ cooperation and/or co-optation of women, the generational divide in place within the Brotherhood movement and how this played out among women, the role that both formal and informal venues for activism play in processes of women’s political empowerment, and the effect of marginalisation, regime repression, and violence, on women’s feminist identities. Empirical research for this study was conducted in Egypt in the years 2013 and 2014, and consists of interviews with Muslim Sisterhood activists and leaders, as well as participant observation of activities and meetings of the Sisterhood in Cairo. The research findings indicate that the Sisters maintained an active and crucial role in the Brotherhood movement under all historical circumstances, but it was during times of MB repression that they managed to exercise greater political influence over the MB movement overall. Findings also indicate that the protracted exclusion of women from the political decision-making offices of the movement, amid women’s continued activism and support for the MB, led to the development of more radical feminist identities among some of the women involved. These were manifested in women’s growing demands for greater equal opportunities and roles vis-à-vis their male counterparts, and their involvement in the political decision-making process of the movement. Finally, the study finds that generation is not always an indication of different feminist attitudes among women, and that informal activist circles, as well as women-only spaces, continue to be important venues for female empowerment and leadership in Islamist movements.