Margaret had seven siblings, among them: Elizabeth of Huntingdon, wife of Robert of Brus, 4th Lord of Annandale, and therefore ancestor of King Robert I of Scotland; John of Scotland, Earl of Huntingdon, his father's successor, husband of Elen ferch Llywelyn, daughter of Llywelyn the Great, Prince of Gwynedd, with whom she had a daughter, etc.
Stringer, KJ (1998) [1993]. "Periphery and Core in Thirteenth-Century Scotland: Alan Son of Roland, Lord of Galloway and Constable of Scotland". In Grant, A; Stringer, KJ (eds.). Medieval Scotland: Crown, Lordship and Community. Edinburgh: Edinburgh University Press. pp. 82–113. ISBN0-7486-1110-X.