Duchess of Brittany, Countess of Hereford

Margaret was the second eldest eldest daughter of Henry of Scotland, Earl of Huntingdon and Northumbria and Ada de Warenne. She was the granddaughter of King David I of Scotland and Maud, 2nd Countess of Huntingdon, William de Warenne, Earl of Surrey and Elizabeth de Vermandois.

Margaret married Conan IV, Duke of Brittany, the son of Alan the Black, 1st Earl of Richmond and Bertha of Brittany. They married in 1160 and had one daughter, Constance, who was forced to marry Geoffrey II, who became the Duke of Brittany.

When Conan died in February of 1171, Margaret was a young widow, aged only twenty-six. About two months later, just before Easter of 1171 she married Humphrey de Bohun, the Hereditary Constable of England, the son of Humphrey de Bohun and Margaret de Hereford. Margaret and Humphrey and two children:
Henry de Bohun, 1st Earl Hereford
Margaret de Bohun

Humphrey died in 1181, and Margaret married a third time to Sir William FitzPatrick Hertburn. They married in 1183 and had one son, Sir William de Wessington.

William died about 1194, Margaret died in 1201.

https://en.wikipedia.org/wiki/Margaret_of_Huntingdon,_Duchess_of_Brittany

Margaret of Huntingdon was a Scottish princess and Duchess of Brittany. She was the sister of two Scottish kings, Malcolm IV and William I, wife of Conan IV, Duke of Brittany, and the mother of Constance, Duchess of Brittany. Her second husband was Humphrey de Bohun, hereditary Constable of England. Following her second marriage, Margaret styled herself as the Countess of Hereford.