Hi Sylvia.
The 1851 census for Isabella Gelling at 4 Shaws Brow Douglas, Widow 84 born England. The 1841 for "Widow Gelling" at Shaws Brow age "65" says she was born "Y", but it's the same person because granddau Elizabeth is in both. I think the England birthplace in 1851 strongly suggests the Liverpool baptism is the right one for her.

I've been filling in the Corjeage/Cavendish people that you've mentioned and I've noticed that the IGI has an Alice Cavendish born 30 Jul & bapt 29 Sep 1773 St. Nicholas Liverpool d/o William Cavendish. In my Gelling database, I have an Alice Cavendish marrying a William Gelling 20 Nov 1798 Braddan. They had 10 children 1799-1817 born Braddan, 3 of whom were dead by 1827. I've never been able to figure out either William or Alice and they seem to disappear as a family before 1841. One exception is a daughter Dinah b 1810 who I think had a couple of illegitimate children in the 1840s in Ramsey & Douglas and ultimately married Edward Davies Isaac 22 Oct 1856 at St. Johns Church Liverpool a spinster age 45 father William Gelling shoemaker.

I'm wondering if this Alice Cavendish who married Wm Gelling is the one b 1773 in Liverpool, and possibly a sister to Isabella Corjeage/Cavendish b 1766. I also have a William Gelling b 1775 Braddan s/o John Gelling & Margaret Caroon, who we now know are the parents of Isabella's husband John Gelling b 1767. William received 5 pounds in his father's 1822 will but beyond that I haven't been able to pin him down.

Am I onto something here, or is it just a bunch of coincidences? The names of children of William & Alice Gelling don't particularly help: James, Henry Daniel, Frances, Edward, Richard, John, Dinah, William Joseph, Sarah Elsey, Eliza. No Margaret or Isabella, and John is #5 and William #6. I might be chasing a rainbow here. Hmm.