Their oldest child Kathleen was, I believe, born in 1888. This would suggest they married in about 1887.
Their second child was my grandmother Mary (1890-1926)and their third, and final, child was Dennis (1893-1950).
It is very likely that they were married in St Patrick's RC Church in Crossmaglen as they were both from the Upper Creggan Parish.
Details of this family history can be accessed on the GRIFFIN/QUINN FAMILY WEBSITE (www.jag-genes.myheritage.com