Walter Stewart, 3rd High Steward of Scotland

Walter Steward of Dundonald (died 1246) was 3rd hereditary High Steward of Scotland and Justiciar of Scotia.
He was the eldest son of Alan fitz Walter, 2nd High Steward of Scotland but which wife of Alan's was his mother is not clear. He was the first member of the House of Stuart to use Stewart as a surname, and was designated "of Dundonald".
He witnessed a charter by King Alexander II, under the designation of "Walterus filius Alani, Senescallus, Justiciar Scotiae" and it may be that seal which Nisbet described pertaining to Walter Hereditary High Steward of Scotland. Around the seal it states "Sigill. Walteri filii Allani".
Family.
Walter married Bethóc, daughter of Gille Críst, Earl of Angus by his wife, Marjorie, youngest daughter of Henry of Scotland, 3rd Earl of Huntingdon and his wife, Ada de Warenne. 
They were parents of: