Summers vs Sommers

Elizabeth:

Welcome to Ireland Reaching Out!

Exactness of spelling surnames was not that important in 19th century Ireland. Many could not read or write. I looked up the baptismal records of the children and the transcription of the records for the three children you mentioned showed SOMERS. I also located another likely sibling named Anne and as you can see below, the transcription shows SUMMERS. 

You can look at the records on the parish register here      https://registers.nli.ie/parishes/0565 ;  

Roger McDonnell

Name:Anna SummersDate of Birth:
Date of Baptism:28-Jan-1856Address:
Parish/District:RIVERSTOWNGender:FemaleCountyCo. Sligo
Denomination:Roman Catholic
Father:PatrickMother:Margaret SummersOccupation:
Sponsor 1 /
Informant 1:Henry Doogan Sponsor 2 /
Informant 2:Maria Samers 

Elizabeth:

Not sure why the link is not working (it did not work for me either). Second try.  https://registers.nli.ie/parishes/0565 ;  If this link does not work, try the main NLI link  https://registers.nli.ie/ ;  Enter Tawnagh in the search box on the upper right.  

I found the baptismal records on the subscription site Roots Ireland. See transcriptions below. Riverstown and Tawnagh are the same parish.

Roger

Name:Catherina SomersDate of Birth:
Date of Baptism:29-Jun-1853Address:
Parish/District:RIVERSTOWNGender:FemaleCountyCo. Sligo
Denomination:Roman Catholic
Father:PatrickMother:Margaret KellyOccupation:
Sponsor 1 /
Informant 1:Patrick Doogan Sponsor 2 /
Informant 2:Catherina Somers 

 Name:Patrick SomersDate of Birth:
Date of Baptism:23-Jan-1859Address:
Parish/District:RIVERSTOWNGender:MaleCountyCo. Sligo
Denomination:Roman Catholic
Father:PatrickMother:Maria KellyOccupation:
Sponsor 1 /
Informant 1:John Dignan Sponsor 2 /
Informant 2:Maria Bowles 

Name:James SomersDate of Birth:
Date of Baptism:15-Sep-1861Address:
Parish/District:RIVERSTOWNGender:MaleCountyCo. Sligo
Denomination:Roman Catholic
Father:PatrickMother:Margaret KellyOccupation:
Sponsor 1 /
Informant 1:Patrick Dunleen Sponsor 2 /
Informant 2:Bridget Somers 

Notes: