South Africa is grieving the loss of a woman many consider to be the mother of the modern country.

Albertina Sisulu, known as Ma Sisulu, died late Thursday at her home in Johannesburg. She was 92.

Following the announcement, the Nelson Mandela Foundation issued a statement saying,”South Africa has lost a treasure.”

Sisulu was born in the Tsomo district of Eastern Cape in 1918 and moved to Johannesburg in 1940 to train as a nurse. There she met anti-apartheid leader Walter Sisulu. The two married in 1944, with former president Nelson Mandela serving as the best man.

When South Africa's apartheid government jailed Walter Sisulu and Mr. Mandela in 1964, she took up the cause. Sisulu continued to lead despite being jailed, tortured and even banned from meeting with more than one person at a time.

In 1983, Sisulu formed the United Democratic Front, helping to revitalize the anti-apartheid movement.

Sisulu capped off her political career by formally nominating Nelson Mandela for president in 1994 and then serving one term as a legislator in the new democratic government.

Veteran activists say despite facing many hardships, Ma Sisulu kept her family together and always carried herself with grace and dignity.

South African Cabinet Minister Collins Chabane said Friday the state will give her an official, special funeral.

Part of Ma Sisulu's legacy are her children, who continue to play an active role in South African politics.

Her daughter Lindiwe Sisulu is the country's defense minister. Her son max Sisulu is speaker of the National Assembly. And her other daughter, Beryl Sisulu, serves as South Africa's ambassador to Norway.

The family said Ma Sisulu had been in good health and was at the center of family activities at the time of her death.