"Portrait of a Lady, Said to be the Duchess of Marlborough", Peter Lely
Presumed portrait of cristina dudley paleotti (c. 1649-1719)
identification proposed by user ecummenic (talk) based on the comparison with a portrait of that woman (see image below). Date: 17th century. Dimensions: height: 69.2 cm (27.2 in); width: 59.1 cm (23.2 in). Medium: oil on canvas. Collection: Unidentified location. Follower of Peter Lely - Portrait of a Lady, Said to be the Duchess of Marlborough
Author: Follower of Peter Lely (1618–1680) (attribution shown in the auction) Probably Jacob Ferdinand Voet (1639–1689)Source: https://commons.wikimedia.org/