She died on Monday evening, surrounded by friends and family, according to a spokeswoman.
Ms. Mandela has been well-known in recent years for discussing her cancer treatment. She was very candid about her drug abuse background.
Her work was described as inspiring by the Nelson Mandela Foundation.
According to the article, she promoted “awareness about cancer prevention” while also “breaking down the stigma surrounding the disease.”
Ms. Mandela also spoke openly about her difficulties with depression and being sexually molested as a youngster.
She also advocated for improved road safety after her 13-year-old daughter was murdered in a vehicle accident in 2010. She later lost a prematurely born son. She leaves behind four children.
Ms. Mandela, Nelson Mandela’s second wife’s granddaughter, detailed her tale in her memoirs, When Hope Whispers.
She was diagnosed with breast cancer at the age of 32, got therapy, and went into remission, but the illness reappeared.
She revealed last year that she had cancer in her liver and lungs, which had spread to other organs. She was being treated as an outpatient before being admitted to the hospital a little more than a week ago.
“How should I tell my children?” What should I say to them? that I might not get to spend my life as a survivor this time? How can I assure them that everything will be fine when it isn’t? “I’m dying… I don’t want to die,” she said on Instagram a few weeks ago.
Ms Mandela remarked on Kaya FM in April, “I’m learning to be okay with my eventuality.”
Her candid confessions earned her a following on social media, where others paid their respects on Tuesday.
Ms. Mandela was only seven years old when her grandpa was freed from jail after 27 years in imprisonment in 1990.
She had only ever known him as a jailed man, so when he was released, she was overjoyed.
Mr. Mandela passed away in 2013 at the age of 95.