Her origin and first marriage are deduced from Benedict of Peterborough who records that "filia sororis regis Scotiæ Willelmi comitissa Brittaniæ" gave birth in 1186 to "filium…Arturum". Her birth date is estimated from the Rotuli de Dominabus of 1185 which records property “villam de Wissinton” held by “Margareta comitissa…xl annorum”, adding that “comes Britannie habet filiam suam” and that she has “i filium de Humfrido de Buun qui est infra etatem”.
The Chronicle of Melrose records the marriage in 1160 of "Malcolm king of Scotland…his sister Margaret to Conan duke of Brittany". The Genealogia Comitum Richemundiæ records that "Conanus filius Alani" married "Margaretam sororem Willielmi Regis Scotie". "Conan dux Britannie comes Richmundie" confirmed the donation of Plubihan and Plougasnou to Saint-Georges de Rennes by charter to [1156/69], witnessed by "Margarita comitissa, Willelmo filio Hamon, Alano de Rohan, Constancia sorore comitis…". A manuscript which narrates the descents of the founders of Lanthony Abbey records that “dominus Humfridus quartus de Bohun, comes Herefordiæ et constabularius Angliæ” married “Margaretam comitissam Britanniæ”. [Two possibilities have been proposed for a third marriage of Margaret. Firstly, Evans suggests that she was the second marriage of Pedro de Lara, quoting a charter dated "X Kal Feb 1221" (Spanish Era = A. D. 23 Jan 1183) at Anjou which records a donation by "P…comes de Lara…comitisse Marger’ uxori mee consanguinee H...angl’ regis" of "Molmera et Handaluz et Agusinu et Eles et Pulucranke…in Hyspania" to Llanthony abbey, witnessed by "comes Gaufredus Britannie, J. sine terra, J. comes J, Mauricius de Creon senescallus Andeg, J. Didaci comitis". He points out that Llanthony had been founded in 1136 by Miles of Gloucester, whose eldest daughter married Humphrey de Bohun, who was the father of Margaret’s second husband. If this origin is correct, Pedro’s marriage to Margaret was presumably terminated before her death, given his third marriage. The difficulty with Evans’s proposal is the obvious age difference between Pedro de Lara and Margaret of Scotland. Another possibility, which also justifies the connection with Llanthony through the Bohun family and is more satisfactory from a chronological point of view, is that Pedro’s second wife was an otherwise unrecorded daughter of Margaret’s. The second possibility for a third marriage for Margaret with "the Berwickshire thegn" William FitzPatrick of Greenlaw, Westmoreland was proposed by Washington, and accepted by Hedley. The Liber de S. Marie de Calchou (Kelso abbey) lists "Carta Willi fil Patric…in villa de Grenlaw" which records the donation by "M comitisse uxoris mee" to Kelso of land "in Grenelawe quem Lyolfus eq’cius tenuit", while the Pipe Roll of 1184 for Westmoreland records lands owned by by "Countess Margaret". Washington assigns three children to this marriage: "1. Walter de Washington, 2. Sir William de Washington, 3. Marjory who married firstly David de Lindsay (from which marriage descended Sir Robert de Pinkney, a competitor for the Scottish crown in 1291) and secondly Sir Malcolm FitzWaldeve alias de Ingoe".]
The Annals of Burton record the death in 1201 of “Margareta mater…Constantiæ, soror Willelmi regis Scotiæ, mater Henrici de Boum comitis Herefordiæ”. 1
He [Conan Duke of Brittany] married, in 1160, Margaret of Scotland, sister of MALCOLM IV, King of Scofland, and daughter of Henry, EARL OF HUNTINGDON, by Ada or Adeline, daughter of William (DE WARENNE), EARL OF SURREY. He died 20 February 1171. His widow married, 2ndly, before Easter 1175, Humphrey DE BOHUN, Constable of England; she died in 1201, and was buried at Sawtrey Abbey, Hunts. 2
Margaret of Scotland, dau. of Henry, Earl of Huntingdon, sister of William, King of Scots, and widow of Conan le Petit, Earl of Brittany and Richmond. 3