Montefiore was friends with suffragette Adelaide Knight and Minnie Baldock. Montefiore was one of the speaker's at Baldock's Canning Town WSPU group and wrote to support Baldock's 'noble stand' in visiting the Liberal leader in December 1906. Montefiore left the WSPU and joined the Adult Suffrage Society, for which she became honorary secretary in 1909, to support the case for full suffrage not based on financial status but for all men and women over the age of majority (21), rather than the limited option, some argued as a first step of women with property being enfranchised. Montefiore's socialist views were shared by Sylvia Pankhurst whom she kept in contact with after the split with WSPU.