By 1913 Marshall was uniquely placed as a lobbyist, with inside information and sympathetic listeners in every party. Through her the dynamically re-organized NUWSS brought the women's suffrage issue to the fore of public awareness. It pushed the Labour Party to adopt a strong stand on women's suffrage and raised working-class consciousness, re-awakening a long-dormant demand for full adult enfranchisement. Had the general election due in 1915 taken place, NUWSS financial and organizational support for the Labour Party might well have been substantial enough to influence the final results.

These impressive achievements were forgotten by the time Catherine Marshall died in 1961. Even recent research on the period has failed to show the full significance of the issue of women's suffrage, much less Marshall's part in the movement. Jo Vellacott's revealing account of Marshall's political work also includes vivid descriptions of a liberal Victorian childhood, a strangely purposeless young adulthood, and the heady experiences of women who, through the awakening of political consciousness, forged a lifestyle to fit their new aspirations.