I found no marriage but didn't expect to, since in Margaret Lundy's 1880 civil birth record, mother Mary Jane Young's name was written above the word formerly, which had been crossed out. Baby Margaret was baptised in St. Malachy's shortly after birth, I don't know what happened to her. I have no conclusive proof, but there are some circumstantial indicators to suggest the possibility that this might have been a case of an underage mother and older father of different religions, and that the two parties might have been:
- William Lundy the son of John Lundy and brother of John Lundy shown in the 1901 census at 7 Quinn Street - the same address that William married from in 1888 (spouse Catherine O'Neill), William died of paralysis in 1894;
- Mary Young the daughter born in 1866 to boot closer Robert Young and Mary Keenan who may have been the same folk listed in the 1880 Belfast street directory living at 33 Market Street, Mary went on to marry a John McKee in 1888.
I can post links to records if you like, but as I indicated, it's really just no more than speculation.