Hi Sue and Jackie
I think I can shed a bit of light here on some of the family, as I'm pretty sure that the Robert Kelly b 1792, son of James Kelly and Isabella nee Kermode, was the father of Margaret Kelly b 1835 who married Robert Clague, cooper, b 1827 (brother of my g g grandmother) on 31 Dec 1856. They had one child, Ann Jane Clague, who died in July 1858 aged 6 months. Then Margaret Clague nee Kelly died in Feb 1859.
Widower Robert Clague subsequently married the widow of Robert Kelly b 1820 who was an older brother of Margaret b 1835. This widow was Mary Ann (aka Ann) nee Kneale b 1824 Lonan ---- she married Robert Kelly b 1820 on 11 Feb 1845 Lonan, and Robert subsequently died in March 1857. They had 2 children, Mary Ann Kelly b 1845 (Sylvia's g g grandmother) and John Robert 1846-1854.
This is so convoluted that when I was given the information a few years ago (with wills, MIs and headstone photos) I didn't really grasp it, but I've sketched out a little tree in the light of the additional details from the will of Isabella Kelly nee Kermode, and all is now clear. I can scan and send it if you like.
I don't have any details on the children of John Kelly b 1783 (m Ann Cowell 17 May 1818 Braddan ?), so I have no idea whether he had an Isabella. If he did, it would have been from an earlier marriage, and he would have been very young, assuming that Isabella Taggart nee Kelly was born circa 1802. There's no chance that Robert Kelly b 1792 could have been the father of this Isabella because he was way too young.
Jean C