I'm descended from the 'Miss Given' mentioned in your post. My mother's family lived in Markstown. I've tried to piece together the history of the Mark and Given families and am interested in your mention of the same story that I've received. Do you know anything else about the Givens or Marks or when they moved from Scotland to Northern Ireland?
I believe that William Mark and Miss Given's daughter was Rebecca Mark, who then married another Given, from whom my family is descended.