After the Conference, Palthe-Broese became dedicated to the cause of women's enfranchisement and joined the Vereeniging voor Vrouwenkiesrecht (Society for Women's Suffrage). From 1915, she served as chair of The Hague branch's chapter committee of promulgation and hosted a booth to disseminate information about women's suffrage each Monday in the market near the intersection of the Brouwersgracht and Prinsengracht canals. That same year, she participated in the Women's Conference at The Hague, which occurred between 28 April and 1 May, to protest World War I and develop a plan to prevent war in the future. Palthe-Broese chaired the committee to provide accommodations for those attending the conference and met influential foreign feminists like the Hungarian sisters, Franciska and Rosika Schwimmer. An organization was formed at the conference which would become the Women's International League for Peace and Freedom (WILPF).