Image taken from Dovercards, however documentation and dating from The Smithsonian Catalogue of Works
There is a companion portrait of her brother, Rene Kieffer (IAP record 81690256).
Great Expectations: John Singer Sargent Painting Children; 2004-2005
Ormond, Richard and Elaine Kilmurray, "John Singer Sargent: complete paintings; volume 1, The early portraits," New Haven, CT: Yale University Press, 1998, no. 27.
McKibbin, David, "Sargent's Boston," Boston: Museum of Fine Arts, 1956.
Ormond, Richard and Elaine Kilmurray, "John Singer Sargent: complete paintings; volume 1, The early portraits," New Haven, CT: Yale University Press, 1998, pg. 48.