Conversation so far:
When did Winnie Madikizela-Mandela die?
Winnie Madikizela-Mandela died on 2 April 2018 at the age of 81.
How did Winnie Madikizela-Mandela die?
Winnie Madikizela-Mandela suffered from diabetes and had recently undergone several major surgeries. She had been in and out of hospital since the start of the year.
When was Winnie Madikizela-Mandela's funeral?
Winnie Madikizela-Mandela's public funeral service was held at Orlando Stadium on 14 April 2018.

Question: Where was she buried?
Self-contained rewrite: Where was Winnie Madikizela-Mandela buried?