Isabella Mac William Peerage person ID=107794 (b. 1165) Parents unknown daughter Avenal William the Lion Children John de Ros Sir Robert de Ros Sir William de Ros Siblings Margaret of Scotland, Countess of Kent Isabella of Scotland, Countess of Norfolk Alexander II of Scotland Marjorie of Scotland Ada (?) Robert de London Henry Galightly Aufrica (?) Margery Elleforde Christina of Sweden Partners Robert de Ros Robert III de Brus