One of my favorite Irish research quirks concerns when a woman’s maiden name isused in the records, and when her married name is used. In historic Ireland, two systems were in place. The first was the English civil government system. Under this system, women were listed by married names, in tax, land and in probates. The second system was Roman Catholic. In this record keeping, women were supposed to be listed under their maiden names. Technically you should see the mother and any female godparents under their maiden names.
However, the way the church and state were supposed to keep the records, and the way the people on the ground actually kept them can be two different things. Roman Catholic records can be the toughest to sort through.
If you see Patrick Byrne and Mary Byrne as godparents at a baptism, then do not assume they are husband and wife. They might be, but they may also be siblings, cousins or Mary’s maiden name may actually be Byrne. If you see “Patrick and Mary Byrne” as godparents, it’s more complicated. Don’t just assume they were husband and wife. The priest may have been showing Mary’s maiden name was Byrne. To address this, I will look for a Patrick Byrne and Mary having children christened in the parish, and see if her maiden name was Byrne.
These are just suggestions. You may have to develop your own research strategy. That’s a very important part of research.