This portrait of Ethelreda Harrison (see RN53) has been attributed by Oliver Millar to Enoch Seeman, characteristics of whose work it shares, notably in the handling of pigment and the modelling of the eyes, lips and other facial features. The portrait probably dates to c.1730 when the sitter was in her early twenties, by which time she was married to Charles Townshend, later 3rd Viscount Townshend.

Seeman, who was born in Danzig (now Gdansk, Poland) into a family of artists, accompanied his father to London in 1704. By 1730 he was established as a portraitist in court circles and fashionable English society. Among his female portraits, RN56 may be compared to those of Lady Catherine Poulett Parker of c.1725 (National Trust, Saltram, NT 872247), Mary Hungate, Lady Gascoigne of 1728 (Lotherton Hall, Leeds Museums and Galleries) and Julia Calverley, Lady Trevelyan (National Trust, Wallington Hall, NT 584399). In terms of the sitter’s appearance, a similar likeness to RN56 is to be found in Jean Baptiste van Loo’s portrait of Ethelreda Harrison (Sotheby’s, London, 8 November 1995 [40]), a mezzotint engraving of which was made by John Faber Jr in 1742 (National Portrait Gallery, NPG D40070).