RC records for Ballinasloe (Creagh & Kilclooney) go back to about 1820. The records are available in the National Library on microfilm Pos. 2432. Copies of the baptisms also seem to be available in FamilySearch centres - ref 1279217 item 9-17
It might also be worth checking the pay-website at
RootsIreland, as they have transcripts of many Galway parishes.
Early baptism records dont give much details so it might not be easy to trace the correct family without a more definite location..it's possible that Maria was just living and/or working in Ballinasloe at the time and was born elsewhere..
Have you tried the 1911 census ?
Shane