Looking for Info Family of Flannery Marion Mary Maria B 1908 Castle Mayo Ireland M G Larkin

Looking for information on family history of my grandmother, maiden name Flannery. Married to George F. Larkin in 8/13/29, Newark, NJ. Died in Plainfield, NJ in May of 1979. She was called Marion, but i remember her telling me about having to change her name because there where many Mary's at the hospital she worked in. Also her papers show different names, one with Marie, another Marion. She had 2 sons, my father, George F. Larkin and Patrick Larkin. She received letters from a much loved sister in IReland.. Postmarked Caislean an Barraigh. I'd appreciate any info offered that might help me pick up the family line on that side of the ocean.