She was born in Gilsland, the daughter of Sir Thomas Dacre (1410–1448) and Elizabeth Bowett.
[1] Joan Dacre married Sir Richard Fiennes in June 1446.
[1] Later, a dispute arose between Sir Richard and Humphrey Dacre, Joan's uncle, regarding the barony.
King Edward IV decided the matter in 1473, by confirming the Barony of Dacre to Sir Richard Fiennes and Joan, while the manor of Gilsland was adjudged to Humphrey, who had previously been liberated of the attainder.
[2] Children of Joan Dacre and Sir Richard Fiennes:[3] Joan died at Herstmonceux Castle, Sussex, England on 8 March 1485/86,[4] and was succeeded by her grandson, Sir Thomas Fiennes, 8th Baron Dacre.