Name: Mary DOUGLAS 1
Birth: ABT 1401 in Mar, Aberdeenshire, Scotland
Death: BEF 1448
Mary Douglas; m. Sir David Hay of Locherworth and Yester, d. between 3 Apr and 2 Sep 1478. [Magna Charta Sureties]
Burke's Peerage has Elizabeth marrying John Hay 2nd (probably after 1448 when Alexander Forbes died). However Magna Charta Sureties states that Mary Douglas (definitely a different person than Elizabeth-because it also shows Elizabeth marrying Alexander Forbes) married John Hay. Mary is of the same parents, ie. Elizabeth's sister.
Note that if (as Burke's Peerage maintains) Elizabeth and Mary are the same person, then John and other offspring of her marriage to David Hay would be born after 1448, because that was when her first husband died and only after that date might she have had a 2nd marriage to David Hay.
I think that MCS is right: Mary Douglas m. David Hay; while her sister Elizabeth Douglas m. Alexander Forbes. Maybe Elizabeth married David Hay after Mary's death.
Father: George DOUGLAS , 1st Earl of Angus b: BEF 1378 in Mar, Aberdeenshire, Scotland
Mother: Mary STEWART , Princess of Scotland b: ABT 1382 in Rothesay Castle, Isle of Bute, Scotland
David HAY , of Lochorwart & Yester, Sir b: ABT 1400 in Lochorwart Castle, Gorebridge, Midlothian, Scotland
in 1st husband 1st wife 1
- Janet HAY b: ABT 1422 in Yester Castle, Gifford, East Lothian, Scotland
- John 1st Lord HAY , of Yester, Sir b: ABT 1426 in Wester Hoprew, Peeblesshire, Scotland
- Title: Magna Charta Sureties 1215, Frederick Lewis Weis, additions by Walter Lee Sheppard Jr, 5th Edition, 1999