Richard, marie Stopes was indeed a hero of the feminist movement.
A short biography is here http://www.spartacus.schoolnet.co.uk/Wstopes.htm
An extract
Marie argued that marriage should be an equal relationship between husband and wife. However, she had great difficulty finding a publisher. Walter Blackie of Blackie & Son rejected her manuscript with the words: "The theme does not please me. I think there is far too much talking and writing about these things already… Don't you think you should wait publication until after the war? There will be few enough men for the girls to marry; and a book like this would frighten off the few." Blackie objected to passages such as, "far too often, marriage puts an end to women's intellectual life. Marriage can never reach its full stature until women possess as much intellectual freedom and freedom of opportunity within it as do their partners."

It was not until, March 1918, that Marie Stopes found a small company that was willing to take the risk of publishing Married Love. The book was an immediate success, selling 2,000 copies within a fortnight and by the end of the year had been reprinted six times. Married Love was also published in America but the courts declared the book was obscene and it was promptly banned.

Marie's next book was about birth-control. She had become interested in this subject after meeting Margaret Sanger, a birth-control campaigner from America. Sanger had been converted to socialism, while working as a nurse in the slums of New York. She observed that many women died of self-induced abortions or raised large families in poverty.