"her lace fichu"
Portrait of Mrs John Winthrop by John Singleton Copley, 1773 (she is wearing a lace fichu)
Public DomainPortrait of Mrs John Winthrop by John Singleton Copley, 1773 (she is wearing a lace fichu)

 A lace fichu was a type of neckline popular in women's fashion in the late eighteenth century. Later, a fichu came to mean a kind of short shawl, popular in Victorian times.