Her family was by her side‚ family spokesman Victor Dlamini said.
On Tuesday, Buthelezi responded to Madikizela-Mandela's death.
Over the years, Madikizela-Mandela became a symbol of the suffering caused by South Africa's system of white minority rule known as apartheid and became a force against it, ultimately serving as a member of parliament.
The Nigeria Association of Women Journalists (NAWOJ) has urged African women to emulate the bravery, confidence and resilience of late anti-apartheid fighter and former wife of late President Nelson Mandela, Winnie.
They say that history will judge a person, and now that the people's heroine is no more, we can honestly reflect on the contribution and sacrifices she made for this country.
Few ordinary South Africans focused on the darker chapters of her past, including a conviction for kidnapping and assaulting an activist found with his throat cut near her Soweto home.
Aptly described as the Duchess of anti-apartheid campaign, she was born to a Xhosa family in Bizana and became a social worker.
Recently she had been awarded the Order of Luthuli, one of South Africa's highest honors.
Gallo Images Winnie Madikizela-Mandela with her daughter, Zindzi Mandela and son, the late Makgatho Mandela after visiting Nelson Mandela Victor Verster prison in Paarl in 1990. It said it will release details of her memorial and funeral services when they are finalised.
"She stood by her former husband Nelson Mandela throughout his stay in prison". I was taken to the gym, to watch him sweat!
She and Mandela separated in 1992 and her reputation slipped further when he sacked her from his cabinet in 1995 after allegations of corruption.
Pre-eminently, as wife of Nelson Mandela she was forthright in her criticism of the truth and reconciliation process as, in her reckoning, neither could bring about "true reconciliation".
Madikizela-Mandela was quoted as saying that Machel should not inherit Mandela's property in Qunu because she owns "a whole world in Mozambique", and she went to court to fight for the home in Qunu.
And as the ANC's "moderation" in office and failure to confront the centres of power led to mass anger, Madikizela-Mandela spoke out.
According to a family spokesperson, she will be laid to rest on April 14 in Gauteng Province. The scale of her influence changed in 1957 when she was 22 and the 40-year-old ANC leader Nelson Mandela caught sight of her waiting at a bus stop.
In 1986, she was widely linked to "necklacing", when suspected traitors were burnt alive by a petrol-soaked auto tyre being put over their head and set alight.
She was among candidates for ANC deputy president in 1997, a position that would have teed her up for a top national leadership role, but withdrew her bid after failing to secure sufficient support. "He loved her to the end".
In her book "100 Years of Struggle: Mandela's ANC", Heidi Holland suggested that Madikizela-Mandela was "perhaps driven half-mad by security police harassment".