Learned some more about the octet of Gelling children of Thomas & Elizabeth (Craine):
1. Ann is not as I described. She was with her parents in 1841 & 1851 and likely matches the burial 5 Feb 1861 age 36.
4. Elizabeth buried 10 Jul 1867 age 38.
6. Sarah is the one who married John Cowle 1857 and died 1859. I missed the fact they had a son William Thomas Cowle in 1858, who is not with his widower father in 1861. Instead, he is with a Lace/Gelling family who is related to Couple #3 Thomas Gelling & Elizabeth Kelly. Furthermore, John Cowle then married Elizabeth Gelling later in 1861 and she is a granddaughter of the same Couple #3. The son of the 1st marriage is with them in 1871 along with their own subsequent children.
7. Margaret md Isaac Corkish had 9 children. In 1881 they are living very close to Edward Gelling widr 69, who is a son of Couple #3.
8. William never married. He was a Lead ore Washer in Patrick and was buried in 1908 at Braddan. In 1891 he lived very close to Edw Gelling's daughter Margaret, of Couple #3.

In other words, it sure looks like there is a close connection to relatives of Couple #3 and I now think this particular Thomas belongs to that family, and not to John Gelling & Isabella Cavendish.