There are uncreated children and John was the apparent ancestor of the Robertson's of Muirton and Gladney...see Donnachaidh Families, below pg 5.
Some sources place Margaret as the daughter of the first wive[1] but more reliable sources contradict this[6] as does the timeline.
Sources
↑ 1.01.11.21.31.4
MacFarlane, Walter, "Genealogical Collections concerning Families in Scotland made by Walter Macfarlane 1750-1751", Edited by James Toshach Clark, Edinburgh: University Press, 1900, Vol. II, Archive.org,
p. 309
↑Burke, John Bernard, "A Genealogical and Heraldic Dictionary of the Landed Gentry of Great Britain and Ireland", London: Henry Colburn Publishers,1863, Ed. 4 Part II, Archive.org,
p. 1278
↑Burke, John, "A Genealogical and Heraldic History of the Commoners of Great Britain and Ireland", London: Henry Colburn Publishers,1838, Vol. IV, Archive.org,
p. 420
↑
Robertson, James Alexander, "Comitatus de Atholia: The Earldom of Atholl : Its Boundaries Stated, Also, the Extent Therein of the Possessions of the Family of De Atholia, and Their Descendants, the Robertsons : with Proofs and Map'", Edinburgh: private, 1860, Archive.org,
p. 40
↑Paul, James Balfour. "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", Edinburgh: David Douglas, 1911, Vol. VIII, Archive.org,
p. 273
↑ 6.06.1Paul, James Balfour. "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", Edinburgh: David Douglas, 1904, Vol. I, Archive.org, p. 442