Like her parents, she joined the Communist Party,[1] which was allied with the African National Congress in its struggle to overthrow the apartheid government of South Africa.

[1] Through investigative journalism, First exposed the racial segregation policies known as apartheid, targeting black South Africans following the rise of the National Party in 1948.

[2] In 1949, she married Joe Slovo, a South African anti-apartheid activist and Communist, with whom she had three daughters, Shawn, Gillian and Robyn.

[1] First was one of the defendants in the Treason Trial of 1956–1961, alongside 155 other leading anti-apartheid activists who were key figures in the Congress Alliance.

In November 1978, First took up the post of director of research at the Centre of African Studies (Centro de Estudos Africanos), Universidade Eduardo Mondlane in Maputo, Mozambique.

[6] She was assassinated by the order of Craig Williamson, a major in the South African Police, on 17 August 1982, when she opened a parcel bomb that had been sent to the university.

[9] First's book, 117 Days, is her account of her arrest, imprisonment and interrogation by the South African Police Special Branch in 1963.

[13] In March 2011, the country of The Gambia issued a postage stamp in her honour, naming her as one of the Legendary Heroes of Africa.