A Catalogue of Paintings in the Collection of Jules S. Bache. New York, 1929, unpaginated, ill.
A Catalogue of Paintings in the Bache Collection. under revision. New York, 1937, unpaginated, no. 63, ill.
A Catalogue of Paintings in the Bache Collection. rev. ed. New York, 1943, unpaginated, no. 63, ill.
An American Correspondent. "English Portraits in the Jules Bache Collection." Connoisseur 113 (March 1944), p. 54, ill., as Mrs. Charles Frederick, who married in 1773 and "would appear to have been painted just after Romney's return from Italy in 1775 and before [her] departure for India in 1777".
Barry Maclean-Eltham. George Romney: Paintings in Public Collections. Kendal, England, 1996, p. 29, as painted about 1776.
Katharine Baetjer. British Paintings in The Metropolitan Museum of Art, 1575–1875. New York, 2009, pp. 124–25, no. 55, ill. (color).
Alex Kidson. George Romney: A Complete Catalogue of His Paintings. New Haven, 2015, vol. 1, p. 229, no. 482, ill. (color), suggests identifying it with the three-quarter portrait recorded by John Romney in his Rough Lists under 1776 as "[Mr/Sir Charles] Frederick," noting that this might be based on an entry in Allwood's frame book of July 23, 1777, for "A 3/4 . . . for Sir Charles Frederick," adding that although John Romney could have assumed this was for a portrait of Frederick himself, Frederick could have been paying for a frame for his daughter-in-law's portrait; states that it appears unfinished and may have been fitted in just before the sitter and her husband left for India, explaining its absence in the sitter books.