Searching Mary Myers Birth

Hi All 

I am coming to Ireland in the next few weeks to visit my partners family. While I am there I am wanting to search for the birth certificate of my 2xGreat Grandmother 

Mary Myers

1827–1899

BIRTH 1827 • Cashel (Caiseal), Tipperary, IRELAND

DEATH 25 AUG 1899 • Onehunga, Auckland, New Zealand

What I know is she married Thomas Patten in church of St John Cashel in Feb 1846. They record Mary's Father as Thomas Myers. They had a child Thomas Patten Jan 1847 who passed in 1848 plus had another child Mary Ann Patten Feb 1848 in the same church. On Mary's record she was residing in the Green in Cashel and the sponsors were Thomas Bourke and Mary Marckle? 

They came to NZ March 1849.

On Mary's Death cert the Mother is recorded as Nora Dwyer and Father James Myers (not thomas?)

I have also connected with a DNA match family in the USA who coincidencally has a Grandparent of the same generation and with the same name as Nora/Hanora Myers est birth 1790. 

I have found I think a Hanora with children believed to be the one born 1790 who went to the USA (they ended up liing in Troy Pensylvania) with 5 boys the story is said.... but not all of them are found... who I believe to be as attached. We are nto certain of this connection as Mary Myers is not in the records we have found. I have also attached one of the boys children prior to going to the usa. We have not found passenger lists for this lot either.

We have also found the Cashel Rate book 1849 which has Nora Myers on page 13 and Hanora Dwyer on page 111 I am not sure how to use this to confirm or deny these are the people I am following. I have also found in the Griffiths Record that we have a Thomas Myers living in the Green (note this is mentioned on Mary Ann Patten baptism as well as Michale Miers Baptism) Note we have nothing to suggest the Nora Myers in the USA is married to a Thomas Myers from the USA family except what I have found on find my past.

I was wondering is anyone can help take the next step so I know where I can look when I get to ireland. 

Also I have a bit of info I have been collecting for theories I would love to meet someone with knowledge of this area in Tipperary who could help me look into other options or family links to these families.

Thank you in advance I look forward to anything small bit you can help with.

Vereana