From about 1909 to 1924 Robertson attended the Art Association of Montreal, where he studied with William Brymner and Maurice Cullen, but unlike many of her fellow students, she did not visit or study in Europe. She was a highly regarded member of the Beaver Hall Group and later of the Canadian Group of Painters. Ill health limited her output to two or three canvases a year. A letter written in 1931 to Eric Brown, director of the National Gallery, gives a sense of her difficulties in gaining recognition: “If it had not been for you and the Group of Seven…I would surely be sunk in oblivion”.
Robertson was a constant source of knowledge, advice and support of the Beaver Hall Group. Her close friend Prudence Heward regularly sought her opinion, as did A.Y. Jackson, when selecting exhibition pieces. Difficulty walking due to illness caused her to discontinue outdoor sketching in her last years. She died in Montreal in 1948.
In a tribute to Robertson in 1949, A.Y. Jackson wrote, “Among the talented students who worked under William Brymner in Montreal, Sarah Robertson was one with outstanding ability. She developed a very personal form of expression, mostly in landscapes with figures and paintings of flowers”.
She painted portraits, still lifes, and murals for private houses, but was primarily interested in landscapes. Idyllic childhood days at the family country house, frequent visits with her close friend Prudence Heward at Fernbank, with Nora Collyer in the Eastern Townships, and in Vermont, inspired her work. There were often sketching trips with A.Y. Jackson, Heward and Collyer to the Laurentians, the Lower St. Lawrence region, or to Nova Scotia. Near her home in the city she found more subject material: hollyhocks in a garden, views from her window, and city landmarks such as the fort of Sulpician seminary.
Robertson was noted as a colourist who at times used black drawing effect. As she matured he painting became freer and bolder. Arthur Lismer noted her Modernist tendencies: “She has the courage to create landscapes and not copy them literally”.
Source: Evelyn Walters, The women of Beaver Hall. Canadian modernist painters, Toronto: Dundurn Press, Toronto, 2005