At the invitation of Lourdes Pintasilgo she worked at the Commission for Social Policy on Women, which had been created in September 1973, commuting between Coimbra and Lisbon. After the Carnation Revolution in April 1974 that overthrew the "Estado Novo", the family returned to Lisbon in 1975 and Tavares da Silva continued to work at the commission, then renamed the Commission of the Female Condition (CCF). That year had been declared by the United Nations as the International Women's Year and Pintasilgo appointed Tavares da Silva to be in charge of its preparation in Portugal. The first World Conference on Women was held in June 1975 in Mexico City on the theme of "Equality, Development and Peace" and Tavares da Silva represented Portugal together with four others including Maria Alzira Lemos. Standing in for Pintasilgo, who was unable to attend at the last minute, and with little experience of public speaking, Tavares da Silva delivered Portugal's address to the Plenary of 3000 people. She would also participate in the Second World Conference on Women in Copenhagen in 1980.