Mary, daughter to George Villiers, first Duke of Buckingham; wife of James, fourth Duke of Lennox, and third Duke of Richmond, who left her a widow secondly in 1655. She had previously married Charles Lord Herbert; and she took for her third husband Thomas Howard, brother of the Earl of Carlisle. (Warrington)
Her portrait: http://www.npg.org.uk/live/search/person.asp?Li...
Chart showing the number of references in each month of the diary’s entries.