Mary O’Brien Harris (1865-1938) was a founder member of the Socialist Quaker Society (along with her husband J. Theodore Harris), a member of the Labour Party, part of the Fabian Society executive committee, and a member of the War and Social Order Committee. She wrote several tracts for the Socialist Quaker Society. She had been educated at Somerville College, Oxford, and was principal of Clapham Girls’ Academy. She also had a strong interest in the Montessori approach to education.
O’Brien Harris was one of the members of the War and Social Order Committee who particularly emphasised the importance of “development of personality” and education. She is recorded in the Committee’s minutes taking the author of a major interchurch statement on social justice to task, for the statement’s lack of reference to women’s role in social and political life.
London Wiki have a short biography.