Young and Spence campaigned in Sydney in 1900 for the Hare-Spence method to be used for federal elections, staying with Rose Scott, and after Spence's death Young completed and published Spence's unfinished autobiography. Young joined the Australian Red Cross Society, the South Australian Soldiers' Fund and the Wattle Day League (WDL) during World War I and directed a three-day exhibition for the WDL's motor ambulance committee in 1916. She left her husband, who had disagreed with her fervent nationalism, in 1917, although he continued to lend her his support. A justice of the peace from 1917, she was secretary of the Women's Representation League in 1918 and was an active member of the board of the Public Library, Museum and Art Gallery from 1916, finally retiring (when almost blind) in 1928. In 1930 she founded the Proportional Representation Group.