Susan Langdon (also known as Valerie Susie Reece, 1852–1910), daughter of a Devonshire butcher and victualer, married Sir Henry Bruce Meux, 3rd Baronet, a brewer. A colorful figure in society, she once created a sensation by appearing at a hunt riding an elephant. This is the second of three portraits Whistler made of her. The first portrait, Arrangement in Black and White, is in the Honolulu Academy of Arts, and the third apparently was destroyed by the artist before it was completed as the result of a quarrel with the subject.
Source: The Frick Collection, Handbook of Paintings, New York: The Frick Collection in association with Scala Publishers, 2004.