Reviewer Adolfo Mascarenhas describes her from a photograph he encountered in her 2018 English-language biography: "...there she was, more standing than leaning on a Morris Minor sedan of the 1950’s, tallish, determined jaw, crossed legs, a shortish white skirt topped by a polar necked long sleeved blouse.

At the time of the Carnation Revolution of 25 April 1974, which also erupted in Angola following the overthrow of the Marcello Caetano's government in Portugal, Valles was participating in a congress in Moscow.

In Luanda she was considered to be part of the ideologically more-orthodox wing of the People's Movement for the Liberation of Angola (MPLA), seen as pro-Soviet, which was directed by Nito Alves and José Van-Dunem.

By 1976, Alves was the new MPLA government's interior minister while José Jacinto Van-Dúnem, an ex-political prisoner, was a key political commissar in the army.

Her execution was preceded by her abject torture and rape by men of the Angola Information and Security Directorate (DISA), the regime's political police.

[3] In September 2020, the BBC carried an interview with João Ernesto Van Dunem (the son of Sita Valles) in the Newshour Sounds programme titled "My parents were killed in Angola's secret massacre".