Sir John Rattray of that Ilk, of Rattray. 11th Laird - Which mother?

It is possible that the profile of Sir Silvester Rattray of that Ilk was merged in error. This is suggested by the charter evidence that follows. Sir Silvester was married to Margaret Ogilvy, and his son by Margaret Ogilvy, possibly his second son, who also named Silvester Rattray, was married to Alison Hepburn.

8 February 1491-92: REX confirmavit cartam Margarete Ogilby sponse Silvestri Rettra de eodem militis, — [qua, — amore filiali, etc., ac cum consensu sponsi sui, — concessit filio suo SILVESTRO RETTRA, et ALISONE HEPBURNE ejus sponse, — terras de "Wemys, cum sale et carbonibus earundem, vic. Fiffe, — pro ejus servitiis : — Tenend. dictis Silvest. et Alis. et eorum alteri diutius viventi et heredibus eorum inter ipsos legitime procreatis, quibus deficientibus, heredibus legitimis et propinquioribus ipsius Silvestri sponsi dicte Marg. quibuscunque, a dicta Marg. de rege : — Reservato libero tenemento dicte Marg. : — Test. Joh. Hering de Wormot, Wil. Hering de Fornocht, Geo. Spens, Hen. Quhite, et D. Joh. de Kynmonth capellano ac notario publico : — Apud Perth, 31 Maii 1491.

An Abstract in English follows:

Charter under the Great Seal of Scotland by which James IV, King of Scots, confirms that Margarete Ogilby, wife of Sir Silvestri Rettra of that Ilk, with the consent of her husband, has given the lands of Wemys, and the charcoals thereof, to her son Silvestro Rettra and his wife Alisone Hepburne. This land was to be held by Silvestro and Alisone and their lawful male heirs, whom failing by the nearest lawful heirs of Sir Silvestri Rettra of that Ilk and his wife Margarete Ogilby. Margarete Ogilby held Wemys as the tenant-in-chief of the King. She reserved her own liferent.

Source Reference:

Registrum Magni Sigilli Regum Scotorum. Register of the Great Seal of Scotland. A. D. 1424-1513. Edited by James Balfour Paul, Advocate, FSA. Scot (H. M. General Register House, Edinburgh, 1882), charter number 2081 on p. 440.

https://archive.org/details/registrummagnisi02scot/page/440/mode/1up

Stirnet’s report (which follows Burke’s Landed Gentry) identifies Margaret Ogilvy’s husband as Sir Silvester Rattray, tenth of that Ilk.

https://www.stirnet.com/genie/data/british/qr/rattray01.php