Hi Bruce , I have done a little checking and found 12 children of John Kinvig and Margaret Harrison !!!

1807 Thomas
1810 Elizabeth
1812 John
1814 Ann
1815William
1818 Richard
1820 Catherine
1822 Edward
1823 Isabella ***
1826 Margaret (our family connection)
1828 Matthias
1831 George

I'm glad I wasn't buying the Xmas presents !!!

I could only find 6 births for Thomas Kinvig and Elizabeth Clague :
1779 John
1784 Thomas
1788 Elizabeth
1789 Catherine
1792 Catherine ( First one died ??)
1795 Edward who dies 1796

***So William Harrison and Isobel Taubman could be Marg Harrison's parents

And I am pretty confident Thomas and Elizabeth Clague are the right parents .

Had difficulty trying to find the right Elizabeth Clague , no births Arbory , 2 in Malew , 1 Douglas and 1 Kirk Michael it could be any of them .

Cheers
David