The daugher of John William Mackail (1859-1945), classical scholar and Oxford professor of poetry, and Margaret Burne-Jones, Angela grew up surrounded by writers. Her godfather was J.M. Barrie, and Rudyard Kipling was a cousin. She married the concert singer James Campbell McInnes (1874-1945) in May 1911, six weeks after meeting him. The present drawing was executed towards the end of their marriage, which ended in divorce in 1917. In December 1918, she married a young Tasmanian engineer, George Lancelot Allnutt Thirkell (1891–1959), and in January 1920 they sailed for Australia with her two sons.
It was in Australa that she began to write, producing articles and short stories for both Australian magazines, journals, and radio, and for the Cornhill Magazine in London. In 1929 she returned to England permanently, where she earnt a living as a journalist, and from the early 1930s onwards, a novelist. She adapted the world of Anthony Trollope's Barsetshire into a series of novels which were highly successful both in the U.K. and in America.
According to Thirkell's biographer, this drawing was considered a great success: 'Everyone remarked upon it. He [Sargent] had exactly captured Angela's pride and vulnerability: her swan neck was elongated, her mouth tremulous; there was a fierce gaze in her eyes. (Strickland, op.cit).