The only clue so far on
Katherine's origins are the comments in an article in
The Mariner's Mirror (see her husband
Adam Rae's page for more details) where it is suggested she was of the Edinburgh
Morrison merchant family. That sounds like it would be the same family that gave rise to the "Morisons of Prestongrange". From a combination of the
Red Book of Scotland and the details on p108 of
Electric Scotland's Morrison genealogy we deduce that John Morison (1515-1573) of Edinburgh merchant and burgess married Beatrix Hill and had a son John from whom descend the Morisons of Prestongrange. Perhaps John (the elder) and his wife Beatrix had another son who was the father of
Katherine subject of this page (and her sister Janet - see
Mariner's Mirror again).