I was searching for a good reliable source that Mariota Duffus (b. ca. 1475) was the mother of George Gordon (b. ca. 1500), Captain of Badenoch and 1st Lord of Beldorney. Are "The Records of Elgin" a reliable source? They show the following record (dated 09 Jan. 1552/53): "1552-3 January 9th. Legitimation grantit be our Souerane Lord James the fyft to Maister William Gordon, thesaurer of Cathnes, and Maister George Gordoun, capitane of Badenoch, his brother [and May (Mariote) Duffus, thair modir, bastard dochter of Sir John Duffus, chaplan] sonis natural of Maister Adam Gordoun." Here's a weblink citing that record: https://patrickspeople.scot/our%20family/18178.htm
Although The Records of Elgin, Vol. 28 and 36 of the New Spalding Club, look to be reasonable sources I'd be hesitant about stating this was absolute proof, without actually seeing the original, as there are some problems with the entry.* For instance, James V can't have granted legitimation in 1552/3 as he was dead by then. Also not sure if the section in square brackets referring to May (Mariote) Duffus, is a part of the original document or a later interpolation?
There is a mention of the legitimation of Mariote Duffous in the Registrum Magni Sigilli Regum Scotorum : The register of the Great seal of Scotland, A.D. 1306-1668. vol. 3, p. 123, dated 24 Feb 1527/28, but although this also mentions William and George Gordon it doesn't appear to specify that she was their mother.
* I can only see Vol 2 of Records of Elgin in full-text and I think any mention of Mariota Duffus is in Vol. 1.