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The fourth record on this page https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1887/10796/5937277.pdf shows the 1887 civil marriage record for Michael and Mary. Michael's father was Mathew (deceased and Mary's father was Michael.
The baptismal records for Killedan/Kiltimagh parish start February 2, 1861. I searched on the subscription site Roots Ireland and did not find Michael's record so likely he was born earlier than 1861. I did find a record for a likely younger brother James. See below and it appears that Mathew Creaby's wife was also Mary Brennan.
The 1855 Griffiths Valuation head of household listing for Killedan civil parish does not show Mathew but there were four Curraby records in Gowelboy for James John Michael and Patrick Curraby likely all relatives.https://www.failteromhat.com/griffiths/mayo/killedan.php
This may be Michael's death record in 1936 https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_returns/deaths_1936/04793/4288824.pdf
I would recommend that you search the free site www.irishgenealogy.ie for civil marriage records and death records for Creaby and you might locate records for siblings of James.
Name:James CreabyDate of Birth:
Date of Baptism:15-Jul-1863Address:GoulboyParish/District:Killedan RC parishGender:MaleCountyCo. Mayo
Father:Mathew CreabyMother:Mary BrennanOccupation:
Sponsor 1 /
Informant 1:Anthony BurkeSponsor 2 /
Informant 2:Kate Brennan