I also have the same problem, my gt grandparents George Wilson and Mary Ann Purdham went from Kirkcudbrightshire to Cork to marry, the father's of both of them went as well, this was in 1968, on the 1871 census they are now living in Cheshire, also one child Isabella born 1868 in Westward, Cumberland, and Julia Annie born 1871.
My parents did talk about a monthly payment being made from the Haig family ( whisky distillery) until the day that she died, but I don't know which child they refer to.
But why did they need to travel to Ireland to wed?
I suspect that the fact they ended up working in a manor house a long way from home was arranged, why?