Nevinson was one of the suffragettes who split from the Women's Social and Political Union (WSPU) in 1907 to form the Women's Freedom League (WFL).
She wrote many articles for the WFL journal, The Vote, and also wrote many suffrage pamphlets including A History of the Suffrage Movement: 1908-1912, Ancient Suffragettes and The Spoilt Child and the Law.
Nevinson was also the first woman Justice of the Peace in London as well as serving as a Poor Law Guardian.