While I can understand the logic in support of Lady Anne de Burgh(or possibly her daughter in law,Lady Joanna Gore,aka Lady Ann Daly),I have accessed portraits of both in a private tree,with the owners authority.While they are both portraits later in life,both feature such strong nasal aquiline features that I seriously doubt it could be either of them.
Later today or tomorrow I will publish some data,which,while not solving the puzzle,will add to the Sutherland family as per the 1844 deed identified by Hallmark.Again,there is an anomaly at the heart of it!
Regards
Roger