Susannah ('Susie') was the daughter of Kate and Arthur Livermore, family friends of the Whistlers in Lowell, MA. She married Edmund Sutton (b. 9 April 1844), and had two children, Ralph (b. 11 May 1881) and Kate Elinor (b. 11 June 1883). The Suttons lived in Manchester, England.
The Livermores and Whistlers were neighbours in Lowell, MA, and developed a close friendship that was renewed in England later.
Arthur Livermore was appointed by President Johnson, US Consul at Londonderry, Ireland, which office he held under successive administrations. He retired in England. Kate visited AMW in London, helped nurse her when she was seriously ill, and visited JW's studio in the 1870s. JW kept in occasional contact with Susie Livermore throughout his life.