Hi Helen
You have a plethora of children to work on, as Michael and his wife Eliza had at least 13.
You ask about tracking teachers and John Grenham offers the following advice on his Site
Researching National Teachers
https://www.johngrenham.com/browse/retrieve_text.php?text_contentid=530
Returning to your observation that Delahunty later became Delahunt, there is another marriage of another [or the same] school master
Coincidentally [or not] school master Michael Delahunt[e] married Jane Scantlebury in the Wesleyan Chapel in Galway City, 22 May 1853.
Badly transcribed at Pay Sites as 'Scantleberry'.
Reminding all that 'transcriptions' are helpful, but must always then be checked against the original document.
This original document is Free at: -
5416452.pdf (irishgenealogy.ie)
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1852/09431/5416452.pdf
If the same Michael, his father was also Michael, a Caretaker.
Michael the Teacher gave his address as Rahoon, and inspection of the Teacher Salary Books, mentioned by John Grenham, requires that information
John Grenham notes these Pay Books end in 1855, too early to be of assistance with the National School at Shinrone.
Assuming that both Michael's are the same, equally supposes Jane died before any second marriage to Eliza Gauntley Gantley.
What of the change in Denomination?
Some then viewed a temporary shift of religious allegiance as a matter between themselves and God!!
Moving from the still speculative to those children there are two sufficiently 'unusual' to warrant notice, Winifred and Matilda Delahunty.
Tracing other occurrences of those names might give you further direction towards other related families.
Michael Delahunty, according to familysearch.org, died in 1891 in Roscrea.
4725595.pdf (irishgenealogy.ie)
https://civilrecords.irishgenealogy.ie/churchrecords/images/deaths_retu…
At age 84 and therefore b abt 1807 this Michael is much older than Michael the School Master, who seems to have been born 1827 - 1834.
Old enough to be the Father of the Master?
But is described as a Labourer.
Apart from these possibilities of further research there is also the possibility of remaking your family through DNA.
I hesitate to suggest DNA.
Too often it has misled researchers by being described as a Golden Key to unlock Ancestry.
The truth is more prosaic.
By itself your DNA simply describes yourself.
Useful only by using DNA as a Matching Device against a large Databank of Users, who hopefully have made some attempt to produce a Family Tree of their own.
Without that Tree you will end up with a Blood Relative.
And another Dead End.
I find that just two companies have provided that sufficiently large Databank of DNA, along with a Databank of Trees, ancestry and myheritage.
Apart from these slim threads I can only wish you Good Ancestor Hunting.
Michael