Sumner grew up between Ollerset, her childhood home in Booysens, Johannesburg, and Eathorpe, her father's ancestral family estate in Warwickshire, England. She completed her schooling at Roedean in Johannesburg and, although she knew from an early age that she wanted to become an artist, she first completed a degree in English literature at Oxford University at her father's insistence. Sumner spen