“… the portrait of his mother, a family group by Lawrence with Stephen and himself as rosy infants” (March 21, 1814)

Sir Thomas Lawrence, Lady Mary Templetown and Her Eldest Son, 1802

Courtesy NationalGallery of Art, Washington

Something along these lines, although created earlier – Justin was born in 1788. Boys did not start wearing trousers until as late as their seventh birthday (see Ian Kelly, Beau Brummell: The Ultimate Dandy, London 2005, p. 54).