Her article in thepeerage is here. Her husband was the 3rd Earl of Cromarty, George Mackenzie. According to his article in the peerage, “…He fought in the Battle of Falkirk on 18 January 1745, where he lead 400 of his clan. On 15 April 1746 at Dunrobin, Scotland, he was taken prisoner. On 28 July 1746 he pleaded guilty to high treason in the House of Lords, and was sentenced to death on 1 August. His titles became forfeit. On 20 October 1749 he received a conditional pardon…"
From Wikimedia; sepia tone removed and imagefixed at 35.65 inches wide at 28.35 pixels/cm.