After being charged with treason and imprisoned, being detained a second time, and barred from publishing, she and her husband went into exile in London, where she joined the Anti-Apartheid Movement (AAM) and organised the World Campaign for the Release of South African Political Prisoners.

[4] Isaacman went to work in the offices of the SACP, where she met Brian Bunting,[1][4] a young World War II veteran and fellow communist.

[4] Appointed as a member of the delegation led by Ahmed Kathrada to represent South Africa, at the 3rd World Festival of Youth and Students, she traveled to East Berlin in 1951.

[4][2] When the trial ended and the defendants were sentenced to prison, she continued to work for their release, through the only "operating office of the SACP in the world",[2] which was headquartered at 39 Goodge Street, London.

[1] Simultaneously, in 1968, she began coordinating the publishing efforts of the African Communist,[2] the quarterly journal of the SACP,[1] while working full time at the Inkululeko Publications.

[1][2] In 1991, after twenty-eight years in exile, the couple returned to Cape Town, when the bans against the SACP and the African National Congress (ANC) were lifted.

[1] In 2010 she was honored by President Jacob Zuma with the Silver Order of Luthuli for her commitment to racial equality, human rights and nation-building efforts in South Africa.