She is sourced by Scotland, Marriages, 1561-1910, Marion Borthwick, marriage date, day, month, 1677, Scotland. Whether Borthwick is derived, or mis typed as Borthuick needs more research than I have the ability/funding to do. From previous researchers notes, I have there were a lot of discrepancies, according to highly qualified experts, at that time, in the translation of the spelling of her surname.
So, there are going to be variations of this surname with sources that need to be examined.