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Here is a link to the civil marriage record for Mchael and Anne https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_ret... The record shows that Michael's father was John and Anne's father was Patrick. Michael was from Errew in Crossmolina civil parish and Anne was from Ballybroony in Ballysakeery civil parish.
Civil registration started in 1864 so for Michael and Anne only baptismal records would possibly be available. Both names are very common.
I searched on the subscription site Roots Ireland and did not find an Anne Walsh baptismal record with father Patrick in the Ballysakeery RC parish records. I also did not find a Michael Collins baptismal record in Crossmolina RC with father John.
I searched the 1901 census for Errew townland but there were no Collins' families. However, Ballybroony had a number of Walsh families likely some had connections to Anne.
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You can also add the story of Michael and Anne to our XO Chronicles site https://www.irelandxo.com/ireland-xo/history-and-genealogy/ancestor-data...