[2][3][4] In 1942, she was a founder, together with Lopes Graça, Benoît and others, of the Sonata Society, which gave public concerts of Portuguese and other contemporary music until 1960, often giving first performances.

[5][6] Cunha married Roger D’Avellar, a pilot working for the Portuguese airline TAP Air Portugal.

[10] Manta was married to Clementina Carneiro de Moura, a member of the Associação Feminina Portuguesa para a Paz (Portuguese Women's Association for Peace - AFPP), as was Francine Benoît, and Cunha also joined this organization.

[5] In November 1946, the Committee of Writers, Journalists and Artists of the MUD delivered to the President of Portugal a petition protesting against censorship, indiscriminate imprisonment and the dismissal of academics and other teachers for their political views.

In March 1947 she signed a letter to the Civil Governor of Lisbon, together with Keil, Cesina Bermudes, Maria Palmira Tito de Morais, Maria Valentina Trigo de Sousa and Elina Guimarães, on behalf of the MUD Lisbon Women's Committee, to protest against the use of political prisons, such as the Tarrafal camp in Cape Verde.