This one is tricky, but I'll give it a go and hopefully someone that knows Irish can help us figure out the rest.
It sounds like there might be slight modifications to the words in some places, but basically, they're singing this:
Tá bean in Éirinn a phronnfadh séad domh is mo sháith le n-ól
Is tá bean in Éirinn is ba bhinne léithe mo ráfla ceoil
Ná seinm théad; atá bean in éirinn is níorbh fhearr léi beo
Mise ag léimnigh nó leagtha i gcré is mo thárr faoi fhód
Tá bean in Éirinn a bheadh ag éad liom mur' bhfaighfinn ach póg
Ó bhean ar aonach, nach ait an scéala, is mo dháimh féin leo;
Tá bean ab fhearr liom nó cath is céad dhíobh nach bhfagham go deo
Is tá cailín spéiriúil ag fear gan Bhéarla, dubhghránna cróin.
Tá bean in Éirinn a phronnfadh séad domh is mo sháith le n-ól
Is tá bean in Éirinn is ba bhinne léithe mo ráfla ceoil
Ná seinm théad; atá bean in éirinn is níorbh fhearr léi beo
Mise ag léimnigh nó leagtha i gcré is mo thárr faoi fhód
I believe the first and third verse are about the same, possibly with slight tweaks.
It sounds like they're either dropping some of the words (or maybe that's just how they're supposed to be pronounced).
For example, in the first verse:
It sounds like Eabha is singing something like "smo" instead of "is mo." Maybe saying it as "smo" is like a contraction or something, similar to how we might say "it's" instead of "it is."
She's also saying what sounds like "sa" instead of "is tá" in the second line of the first verse. Again, that might be an accepted contraction or something.
Lastly, it sounds she's saying "tá" instead of "atá."
If someone wants to pick apart all the words and figure out which ones they're adjusting, have fun.
It'll be much easier for someone that can write and/or speak Irish than someone like myself with almost no knowledge of Irish.