Apologies for the delay in getting back to you and Donna - had to take laptop to be repaired but I'm back in action again now !!
Ok. Yes I do have a copy of the marriage contract between John Cain and Christian Cowley and the contract was drawn up only 14 years after John's baptism - so I'm not sure of his exact age.
I also have the Wills of Cath Cubbon and William Cowley [Christian's parents]. Cath's Will mentions her grandson Wm Caine [1740] and her husband Wm Cowley mentions his grandson John Caine who I am assuming must have been born after the grandmother's death and before the grandfather's [1744]. And William [the first child] possibly died before 1744 and therefor not mentioned in his grandfather's Will. Thus leaving John as the only surviving child.
So I am thinking that the John Caine who married Alice Cannell in 1741 can't be the son of John and Christian Cowley Caine [can he??].
Or am I on completely the wrong track????