This portrait depicts the wife of King Frederick V, and was taken from an engraving of 1748 by Johann Martin Preissler, which in turn was after a painting by Carl Gustave Pilo (1712-92), a historical artist who painted most royal families of northern Europe.
This portrait is considered by many to represent Queen Louise, first wife of King Frederick V; he married his second wife in 1752, so assuming this attribution is correct, a date of circa 1750 would appear appropriate. See Hervouët and Bruneau, La Porcelaine des Compagnies des Indes à Décor Occidental, 1986, fig. 9.102, p. 228, for a plate from the collection of H. Danielsen, Copenhagen bearing this portrait. However, see Michel Beurdeley, Porcelain of the East India Companies, 1962, fig. 89, p. 129 for a similar plate in the Espirito Santo Collection, Lisbon, and a discussion on the identification of the portrait; Beurdely feels confident that the portrait depicted is that of the King's second wife, Juliana Maria, and suggests a date of circa 1760. A plate with this portrait sold in these Rooms, 19 November 1999, lot 367, together with one of King Frederick as lot 368.