MARGARET ([1194]-[after 6 Jan 1233]). The Chronicle of Melrose records the marriage in 1209 of "Alan FitzRoland" and "the daughter of earl David, the brother of the king of Scotland"[492]. The Annales Londonienses name "Margaretam, Isabellam, Matildam, et Aldam" as the four daughters of "comiti David", recording the marriage of "la primere fille Davi" and "Aleyn de Gavei"[493]. John of Fordun´s Scotichronicon (Continuator) records the marriage in 1208 "apud Dunde" of "Alanus magnus de Galweyia, filius Rotholandi" and "Margaretam filiam David comitis de Huntingtona"[494]. The primary source which confirms her appearance in Jan 1233 has not been identified. The date is inconsistent with Alan´s subsequent marital history, unless his marriage to Margaret was dissolved. m (Dundee 1209) as his [third] wife, ALAN Lord of Galloway, son of ROLAND Lord of Galloway & his wife Helen de Moreville (-[2] Feb 1234, bur Dundraynan). Constable of Scotland.
http://fmg.ac/Projects/MedLands/SCOTLAND.htm#_Toc253996189