Yes,
The only really reliable source for this ballad is Mrs Brown and even that ballad is very likely at some point in the mid 18thc to have been translated from the Danish like many another.

Bell Robertson recites too many long ballads that follow Buchan's concoctions to be reliable.
She does provide one very useful piece of information when she states that Jamie Rankin (Buchan's fall guy, whom she knew) hadn't the wit to make up a ballad.