Catherine Creaton 1851 Swineford Mayo daughter of John and Margaret.
but that is the only Creaton/Craatin with variants I found at findmypast.ie
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For the general problem of finding Irish origins of people: My advice is basically look at every record you can get your hands on. Look at all the siblings and cousins who were born in Ireland. Sometimes their records will tell a county of origin. Look for obituaries, records of fraternal organizations.
If any relatives went to the States, look for their passenger manifest. The later ones required a contact person in the country from which the immigrant came. And US death records sometimes will name a county, not just "Ireland".
I found a couple of counties once on "Return of a Birth" slips that a midwife filled out for the board of health. She was Irish and she put down "Co Mayo" instead of just "Ireland."
Look at the composition of the neighborhood your husband's ancestors lived in. Were most people from the same place? A lot of people in my grandfather's neighborhood came from within a few miles of his home in So. Down.
Get a feel for where the surname occurs, I usually use Griffith's Valuation for that.
If you have trouble with place names, google it. like "what is the Catholic parish in --- registration district." Google sometimes suggests a different spelling if that is the problem as well. Get a feel for the County/Registration District/Civil Parish/Townland structure. Google them again, like "County Mayo townlands". There are a lot of helpful sites that tell which place is where.
Catholic parishes are not always the same as the Civil Parish, but they might have the same name.
Try Facebook too. Some of the counties have really good groups. Co. Clare is one, Down is another, I haven't tried Mayo yet. People might recognize the name and be able to put it with a place.
I'll take another look at your post and infomation later today or tomorrow.