In 1968, she was elected in Transkei representing the seat of
Lusikisiki. Prior to the granting of independence, she held a number of portfolios, including energy, education and telecommunications. as a result she taught in a number of schools in
Natal during the 1960s. Even though Sigcau was a part of the
Transkei administration, she still maintained links with the ANC, who were operating from Lusaka at the time. Her father Botha Sigcau was king of the
Mpondo people, who had influence within the Transkei State. A battle for power ensued between the Mpondo chieftaincy and Matanzima's Transkei government. In 1977 she gave birth to her third child after having an affair with Chief JD Moshesh, who was also a government official. Shortly thereafter her father Botha Sigcau died from a long illness. After King Sigcau's death Matanzima was looking to consolidate his authority over the Mpondo people, and he forced Sigcau out of office. Matanzima cited Sigcau and Chief JD Moshesh's affair as a breach of code of conduct for the reasons to recall her from public office. This was met with mixed reactions, given that she was also a widowed princess at the time. After the opening of parliament in 1978 Sigcau led a floor crossing of all Pondoland MPs, and formed the Democratic Progressive Party, but two years later she re-joined the
Transkei National Independence Party, which was still the ruling party at the time. After independence, she held the portfolios of Interior Affairs and Posts and Telecommunications. She became the leader of the Transkei National Independence Party on 5 October 1987 and became the third Prime Minister of Transkei two days later. Then Prime Minister and brother to Kaiser Matanzima, George Matanzima was forced to resign from office due to corruption allegations. She defeated Kholisilie Nota and Ngangomhlaba Matanzima to the position, both of whom were male. Her term as prime minister did not last long as she was overthrown in a coup by General
Bantu Holomisa. This came after Holomisa accused her government of corruption, alleging that Sigcau received bribes in exchange for gambling rights. While she denied these allegations, she conceded to accepting a bursary worth R50 000 from an official in order to pay for her daughter's tuition. ==South African politics==