As Margaret was married before 20 Jul 1459, her birth must have been prior to 20 Jul 1447.
Sources
↑ 1.01.1Paul, James Balfour. "The Scots Peerage : founded on Wood's ed. of Sir Robert Douglas's Peerage of Scotland; containing an historical and genealogical account of the nobility of that kingdom", Edinburgh: David Douglas, 1907, Vol. IV, Archive.org,
p. 403
↑Paul, James Balfour. "The Scots Peerage : founded on Wood's ed. of Sir Robert Douglas's Peerage of Scotland; containing an historical and genealogical account of the nobility of that kingdom", Edinburgh: David Douglas, 1906, Vol. III, Archive.org,
p. 224
↑Fraser, Sir William. "Book of Carlaverock: Memoirs of the Maxwells, Earls of Nithsdale, Lords of Maxwell & Herries", Edinburgh: private, 1873, Vol. I, Archive.org,
p. 586
Crichton-226 and Crichton-225 appear to represent the same person because: I think James Douglas (son) was Elizabeth Crichton-174s son. And Crichton-225 is in error. Margaret is Elizabeth's sister.