Sophie Caird, née Gray, was the sister of Lady Effie Gray, who married the critic John Ruskin and then the artist Sir John Everett Millais. In 1873 Sophie married Sir James Key Caird, a jute manufacturer. They had a daughter Beatrix Ada (1874-1888).
The Cairds were friendly with the Leylands, Captain Moncrieff, Louise Jopling, Nita Gaetano, JW and Beatrix Whistler. In 1894 they invited JW and Beatrix to come and stay with them in Dundee (#00501). Millais painted a portrait of their daughter Beatrix.
Jopling, Louise, Twenty Years of My Life, 1867 to 1887, London, 1925.