He [Robert de Ogle] married, 1stly, Isabel, sister of John DE FERNIELAW, and, in her issue, heir of his grandson John. [Complete Peerage X:24-6, (transcribed by Dave Utzinger)]
Note: I find little information on the Fernielaw name. There is an avenue in Edinburgh, Scotland named after it, which led to "Fernielaw House and farm, which is still located on the west side of the street. Fernielaw Avenue was the driveway to these properties. A field existed here called Jamielaw, later called Fernielaw." I think Isabel may have been Scottish; thus I will place her in Edinburgh?