African National Congress (ANC) stalwart and former KwaZulu-Natal MEC Ina Cronjé died on Tuesday - five days before her 80th birthday.

Surrounded by family and "her beloved cats and dogs who had been guarding her bed", Cronjé died after a short illness, her family said in a statement.

She leaves behind her husband Pierre, daughter Larissa, son Reuben and grandson Mikka.

Her husband said that "for 59 years, we had a full and exciting life, sharing our love for cars, travel and a commitment to the struggle to make South Africa a better place for all".

Her family described her as a "woman of substance, who lived and died on her own terms".

Cronjé worked as a teacher, lawyer, and politician.

She was dubbed "Mama Action" during her tenure as Education MEC and was known as the "no-nonsense" Finance MEC who led the provincial treasury out of the red to a healthy financial position.

Cronjé was a founder member of the first ANC branch in Pietermaritzburg Central after the ANC was unbanned.

As a consequence of her political involvement, she defended many ANC comrades in political trials.

While in public office, the provincial education department received its first unqualified audit opinion since democracy under her leadership.

"Fearless, hard-working and solution-driven. She was one of the most principled people I have known. I salute an incredible woman, who later also became a precious and dear friend," said Christi Naudé, who worked as her media liaison officer, parliamentary officer, speech writer and financial literacy coordinator.

Esther Naidoo, her former personal assistant, said: "It is incredibly satisfying to hear people still talking about her tremendous hard work and notable achievements as MEC for Education and Finance. She was out there for the people and went the extra mile to make a difference."

A private memorial service will be held for her family and close friends. A public memorial service is under consideration, and details will be announced later.