I found the 1874 civil marriage index record for Matthew McConnell and Sarah Mackey The marriage was registered in the Strabane registration district. The marriage was recorded in Volume 7 page 305.
I could not locate the family in the 1901 census were they still in Ireland at that time?
You can get a copy of the above marriage record from the General Register Office for around 4 euros. if you are interested let me know and I will forard instructions.