Isabel Douglas, Countess of Mar in her own right (11th Holder of the title); born c1360; married 1st by July 1388 Sir Malcolm Drummond of Drummond (murdered while confined in prison prior to 8 Nov 1402; married 2nd between 5 and 9 Dec 1404, as his 1st wife, Sir Alexander Stewart, "The Wolf of Badenoch", thereafter 11th Earl of Mar in right of his wife (dspl 25/6 July 1435, having had by an unkown mother Sir Thomas Stewart, Master of Mar....the 11th Earl (as he was to become) had the preceding 12 Aug forced his future wife to sign a charter making over to him, in supposed view of the forthcoming marriage, the Earldom of Mar "and Garioch", with remainder to heirs of their bodies, failing whom to his heirs and assigns (ie. to the exclusion of heirs on her side of the family who had better right); this charter was never confirmed by royal charter, however, and next month the future 11th Earl defeated the Lord of the Isles at Harlaw 1411, was Admiral of the Scottish Kingdom 1419/20 and illegally go the Earldom of Mar regranted to himself and his bastard Thomas 1426), restored to her Kildrummy Castle, which he had previously seized; she granted the Earldom to him and their heirs by charter 9 Dec 1404 (royal confirmation 21 Jan 1404/5), reserving its descent to her own lawful heirs, and dsp Aug-Sep 1308. [Burke's Peerage]
Note: I don't know what "(dspl 25/6 July 1435--no closing parenthesis--obviously a misprint. But it may be implying that Alexander Stewart died much later than generally thought. Of course with a misprint, who knows.