Isobel survived her husband Robert who died in 1232.[3] She did not remarry and she herself died in 1251. She was buried at Sawtry Abbey, alongside her husband and her father.[4]
Issue
Isobel and her husband Robert de Brus had at least 2 sons and a daughter:
Robert de Brus, who became the 5th Lord of Annandale and married Isabel de Clare, daughter of Gilbert de Clare Earl of Hertford and Gloucester; had issue.
Bernard de Brus of Exton, married firstly Alice de Beauchamp, daughter of William de Beauchamp of Elmley, [5]and married secondly Constance de Merston, widow of John de Morteyn;[5] was the father of Sir Bernard de Brus II.[6]
^Society of Antiquaries of Scotland Volume 14, page 345 (2020) The Society of Antiquaries of Scotland [data-set]. York: Archaeology Data Service [distributor] doi:10.5284/1000184
^The Scots peerage : founded on Wood's ed. of Sir Robert Douglas's Peerage of Scotland; containing an historical and genealogical account of the nobility of that kingdom by Paul, James Balfour, Sir, 1846–1931; page 430; https://archive.org/details/scotspeeragefoun02pauluoft/page/430/mode/1up
Miscellanea Genealogica et Heraldica, Volume 1. Hamilton, Adams, and Company. 1874.
Richardson, Douglas (2011). Royal Ancestry, Volume II. Douglas Richardson. ISBN978-1-73139-168-1.