Margaret de Menteith was a daughter of Alexander, Earl of Menteith

Alexander, Earl of Menteith

Alexander of Menteith , son of Mary I, Countess of Menteith and Walter Bailloch Stewart, her husband, was a Mormaer or Earl of Menteith for most of the 1290s. He is first noted with his brother John de Menteith in a compact between Bruce and the Stewarts on 20 September 1286, at Turnberry, Carrick...

 and his wife Matilda. She was the wife of Alexander de Abernethy

Alexander de Abernethy

Alexander de Abernethy was a Scottish baron. He was a descendant of lay abbots of Abernethy; his grandfather Laurence, great-grandson of Gillemichael, Earl of Fife, was the first to style himself Lord...

, a noted Scottish knight and opponent of Robert I of Scotland

Robert I of Scotland

Robert I , popularly known as Robert the Bruce , was King of Scots from March 25, 1306, until his death in 1329.His paternal ancestors were of Scoto-Norman heritage , and...

. She is first encountered in historical records as "lady Margaret de Abrenythy", a lady of the court of Isabella of France

Isabella of France

Isabella of France , sometimes described as the She-wolf of France, was Queen consort of England as the wife of Edward II of England. She was the youngest surviving child and only surviving daughter of Philip IV of France and Joan I of Navarre...

, Queen of England, in 1311/12. She resided in England as late as 30 January 1324/5, when the Calendar of Patent Rolls recorded the grant by King Edward II of England

Edward II of England

Edward II , called Edward of Caernarfon, was King of England from 1307 until he was deposed by his wife Isabella in January 1327. He was the sixth Plantagenet king, in a line that began with the reign of Henry II...

: "Licence for Margaret de Abernythyn to go to Scotland to treat with her friends for the recovery of the lands of her inheritance in Scotland."

Her identity as a daughter of Alexander, Earl of Menteith was first proposed in 2003. Andrew B. W. MacEwen found proof of this identification in 2006, which was published in The Scottish Genealogist in September 2010.

Her issue by Sir Alexander de Abernethy includes two daughters:

• Margaret de Abernethy, wife of John Stewart, Earl of Angus
  Earl of Angus
  The Mormaer or Earl of Angus was the ruler of the medieval Scottish province of Angus. The title, in the Peerage of Scotland, is currently held by the Duke of Hamilton.-Mormaers:...
  
  ; and
• Mary de Abernethy, wife of (1) Sir Andrew de Leslie and (2) Sir David de Lindsay.