She and her cousins Maria Zambaco and Aglaia Coronio were known collectively among friends as "the Three Graces", after the Charites of Greek mythology (Aglaia, Euphrosyne and Thalia), as all three were noted beauties of Greek heritage. It was in the house of the Greek businessman A.C. Ionides (1810–1890) at Tulse Hill, in south London, that Marie and her sister Christine (1846–1884) met Whistler and Swinburne for the first time. They were dressed in white with blue ribbon sashes. Swinburne was so overcome that he said of Spartali: "She is so beautiful that I want to sit down and cry". Marie was an imposing figure, around 1.9 metres (6 ft 3 in) tall and, in her later years, dressed in long flowing black garments with a lace hood, attracting much attention throughout her life.
She modelled for: Brown; Burne-Jones (The Mill); Julia Margaret Cameron; Rossetti (A Vision of Fiammetta, Dante's Dream, The Bower Meadow); and Spencer Stanhope.
In 1871, against her parents' wishes, she married American journalist and painter William J. Stillman. She was his second wife, his first having committed suicide two years before. The couple had posed for Rossetti in his famous Dante pictures, though it is not certain if that is how they first met. She also travelled to America, and was the only Britain-based Pre-Raphaelite artist to work in the United States.
|A Vision of Fiammetta, by D. G. Rossetti|
|The Lady Prays - Desire (self-portrait)|
|Spartali by Rossetti|
|Self-portrait On A Balcony|