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The subscription site Roots Ireland has baptismal and civil birth records for eight children of Nicholas McDonagh and Bridget Jorden. If you don't have the information on names and dates, let me know. Unfortunately, the baptismal records for Kiltimagh parish start in 1861 and I did not find a baptismal record for Nicholas McDonagh. I did find a Bridget Jordan record in 1841 with the parents names listed in Aglish (Castlebar) RC parish. Aglish is about four civil parishes to the west of Kiltimagh/Killedan and Jordan and Sheridan are common names so this could be another Bridget Jordan. At least you have a lead.
Here is Bridget and three children in the 1901 census http://www.census.nationalarchives.ie/pages/1901/Mayo/Killedan/Killedan/1596984/
Bridget died December 1907 https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1908/05501/4541340.pdf
I believe this is Anthony and his wife Ellen in the 1911 census http://www.census.nationalarchives.ie/pages/1911/Mayo/Ardlee/Killedan/738642/
Civil records can be found at the free site www.irishgenealogy.ie
Let me know if you have any questions.