Mathew Nihil Killaoe (Clare) Born Circa 1800

I am researching my father's family and believe I have found his great-grandfather, Mathew Nihil of Killaloe, and great-grandmother Mary Molly(sp) of Portras(sp) in the register's of St. Flannan's. The earliest record I found is the baptism of a son, John, in July 1833. It appears to indicate that he was illegitimate although both parents are listed. In a later register, I found a marriage record for Mathew Nihil and Mary Mockly. Three subsequent children have baptisms registered: Margaret 1844, Mary 1848 and Sarah 1849. All are show parents to be from Killaloe except Sarah. Her record shows the family living in Fishlane. I have not found a record for son, Mathew born around 1836. 

The Nihil's appear to be quite numerous in Killaloe and I am curious about the family before 1833. Given the way the children were named, I suspect that Mathew's father was John Nihil.

John Nihil, born 1833, appears to have emigrated to Troy New York USA around 1848. His father Mathew emigrated around 1850 also to Troy. Both appear to have left from Limerick. Mary Nihil emigrated in 1851 with Mathew and Margaret. There is no emigration record for Mary born 1848 or Sarah born 1849. Given their birth years, I suspect they died in Ireland. Another daughter was born in Troy in 1853 and named Mary.

In Troy, at the time of their naturalization, brothers John and Mathew indicated their last name as Nial which has continued to be the family name. But in the Troy directories and census records they continued to be listed as Nihil and Niles for many years.

Anyway, any additional information would be appreciated.