Helen of Galloway was a daughter and co-heiress of Alan, Lord of Galloway

Alan, Lord of Galloway

Alan Fitz Roland was the last of the MacFergus dynasty of quasi-independent Lords of Galloway. He was also hereditary Constable of Scotland.-Family:He was the son of Roland, or Lochlann, Lord of Galloway and Helen de Morville...

 (d. 1234) and his first wife, a daughter of Roger de Lacy, Constable of Chester. Helen was the first wife of Roger de Quincy, Earl of Winchester

Roger de Quincy, 2nd Earl of Winchester

Roger de Quincy, 2nd Earl of Winchester was a medieval nobleman who was prominent on both sides of the Anglo-Scottish border, as Earl of Winchester and Constable of Scotland....

 (d. 1264). Although Helen was the first of Roger's three wives, his only descendants were three daughters by Helen. The eldest daughter, Margaret, married William de Ferrers, Earl of Derby

William de Ferrers, 5th Earl of Derby

William III de Ferrers, 5th Earl of Derby was an English nobleman and head of a family which controlled a large part of Derbyshire including an area known as Duffield Frith....

 (d. 1254); the second daughter, Elizabeth (or Isabella), married Alexander Comyn, Earl of Buchan

Alexander Comyn, Earl of Buchan

Alexander Comyn, 2nd Earl of Buchan was a Scoto-Norman magnate who was one of the most important figures in the 13th century Kingdom of Scotland. He was the son of William Comyn, jure uxoris Earl of Buchan, and Marjory, Countess of Buchan, the heiress of the last native Scottish Mormaer of Buchan,...

 (d. 1289); the third daughter, Helen, married Alan de la Zouche

Alan la Zouche (1205–1270)

Alan la Zouche Baron Zouche was an Anglo-Norman nobleman and soldier.-Background:He was the son of Roger de la Zouch and the grandson of Alan de la Zouch. This elder Alan, the first of the family to be established in England, was a younger son of ‘Galfridus vicecomes,’ that is, in all probability...

(d. 1270).