Penguin, the song IS in Scottish Gaelic, otherwise known as Gaidhlig. From the information that it was MAry Smith, I would have to say it is most likely Trad. 99% of Gaelic songs fall into the category of Author: Anonymous. Can't help it.

Did you say you have a translation? Would you post that translation? I will see how it compares. Will try to remember to bring in my Gaelic dictionary to start on a translation for comparison.

You are right in that many times a translation will leave something out. We'll see how literal yours is.