Margaret of Scotland was the first child born to William I of Scotland and his Queen consort Ermengarde de Beaumont. She was an older sister of Alexander II of Scotland.
On June 19, 1221, Margaret married Hubert de Burgh. At the time of their marriage Hubert was effectively the Regent of the Kingdom of England since Henry III was an underage King. Henry III finally came of age in 1227 and Hubert retired from his duties as Regent. He was awarded the title of Earl of Kent and remained one of the most influential people at court.
They had only one known daughter:
Margaret de Burgh (c. 1227 - 1237). She is also known as "Megotta". Married Richard de Clare, 6th Earl of Hertford.
She survived her husband by sixteen years and died in 1259. She was buried at the Church of the Black Friars of London.
From her birth to her death Margaret was arguably either first or second heir to the throne of the Kingdom of Scotland as one of the few living, legitimate descendants of William I. However, cognatic primogeniture was not yet the norm in Great Britain and more distant relatives could well claim the throne. As they would in fact do in the Succession Crisis of 1290 to 1292.
Hubert de Burgh