Hi Averil,
Thank you for confirming this information that I located yesterday apart from the land sale records which are interesting.
I actually work in Laxey which is down the hill from Ballarig.
Grettest is now known as Gretch Vane farm up on the Ballarig Road. I will work on the family now that I am convinced they are the ones I am looking for. I saw a suggestion online that maybe your Joney Garret had married William Cottiman but now that you have clarified her situation - I can look elsewhere for my Joney!