Hi Donna,
Happy St Patrick's Day to you also!

I have nothing further about Catherine Sayle, other than the 1841 census:
1841 census Braddan, Corie Choc:
Jane RADCLIFFE 80 Independent (mother Jane d.1744 Andreas)
Alexander RADCLIFFE 45 Agricultural Labourer
Catherine RADCLIFFE 40
Jane RADCLIFFE 15 Female Servant
John RADCLIFFE 15 Apprentice Carpenter
William RADCLIFFE 15 Apprentice Carpenter
Catherine RADCLIFFE 13
Phillip RADCLIFFE 11
Thomas RADCLIFFE 9
James RADCLIFFE 7
Mary RADCLIFFE 5
George RADCLIFFE 2

There is a Cath Radcliffe marriage 16 Dec.1848 Andreas to John CORKHILL, which just misses the date (1849) when details about father, place, and occupation were given in Andreas.
- I don't have access to the 1851 census to follow up this possibility.

We think eldest son John married Elizabeth MAXWELL [Onchan, 1843] and was living in Lonan in 1861, but what happened to the other children is still a mystery. Perhaps Phil will let us know which one was his ancestor, and when the family went to Canada.

I couldn't find George b.1838 later than 1841 in the IOM, but there was one the right age in the USA 1880 census in New Haven, Nelson, Kentucky, but that doesn't help with Cath Sayle!

Sue