This article explores how infant school reform took hold in London's schools from the 1890s to the 1930s through examination of the work of two Froebelian head teachers, Elizabeth Mary Shaw and Frances Emily Roe. In contrast to teacher-led rote-learning methods and rigid discipline they implemented play-based activities drawing on children's interests and introduced visits for nature study and projects. The research draws on logbooks, published accounts, reports of HMIs, local authority inspectors and school managers, and witness evidence submitted by Shaw and Roe for government reports. The data suggest that their work reflects developments in the educational experimentation which marked the period and demonstrates women's agency in challenging conventional conceptions of infant teaching and expanding conceptions of educational spaces. The article illuminates how reform was disseminated and shows that as a result of their success both women achieved high professional status.