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Can you provide the names of the grandparents and were they born in Ireland and what years?
I searched on the subscription site Roots Ireland and did not find any baptismal records for children of Patrick O'Keeffe and a mother with the surname Roach. I also did not locate a marriage record in Co. Kilkenny. I did find an 1810 marriage in Cappoquin parish Co. Waterford. The husband was Patrick Keefe and the wife Catherine Roche.
How does the surname Shortall fit in?