Women in Ḥassāniyya-speaking Sunnī Muslim communities in Mauritania have long served as spiritual guides (muqaddamāt) and as teaching scholars (limrābuṭāt) for other women. Yet those who have done so have tended to come from a small number of prominent scholarly families. Furthermore, their activities have usually remained hidden outside of their immediate social circles and are actively excluded from the historical record. In recent years, however, a boom in Islamic learning has led to a diversification in the social backgrounds of women acting as Islamic teachers and spiritual guides. At the same time, women’s spaces of Islamic learning have become increasingly visible. This article illustrates these changes in women’s exercise of Islamic authority by recounting the life stories of several female spiritual guides and teaching scholars in Nouakchott who adhere to the Tijānī Sufi order. It also draws on historical documents and government survey data to contextualize these changes. The stories presented here highlight important aspects of women’s performance of religious authority. One is the centrality of the concept of “knowing Islam,” which entails familiarity with the Qurʾan and a range of other Islamic texts. Another is the centrality of historical models, especially that of the Prophet’s wife ʿĀʾisha, in offering contemporary women justification for engaging in the teaching and production of Islamic knowledge. Ultimately, however, estimating changes in women’s participation in Islamic knowledge and authority remains a difficult task because it has long been hidden and even actively erased from the historical record.