According to Michael O'Grady's death certificate: Father: Patrick O'GRADY Mother: Elizabeth PURCELL (? Possibly. It's very hard to read)
Margaret O'Grady's death certificate: Father: Patrick CLUSKEY Mother: Ellen CARROLL (interesting side note, the family living near Mike and Margaret in 1870, just after immigration, was Barney CARROLL, and in 1880 census the Carrolls were living next door to Mike and Margaret. Barney Carroll's family and Mike/Margaret all emigrated within about a year of each other, and they are all buried at St. Patrick's Cem in Noblestown.) I do not know if Patrick and Ellen Cluskey ever emigrated, but I believe they remained in Durham, England.