Surtees, A Catalogue Raisonné, vol. 1, 174 (no. 362).
This is the “very careful chalk-drawing of May, which will be worth 100 guineas” that DGR mentioned in a letter to his brother from Kelmscott of 2 November 1872 (see
Fredeman, Correspondence, 72. 106.) See also the commentary for the chalk drawing of May's older sister Jennie, done apparently the year before.