lewis andCatherine Brennan

I am searching for any information on the family of my ancestor Ellen Brennan (born about 1837)and her parents Lewis Brennan and Catherine Claniss.I have searched most of the counties that the name Brennan is most numerous.County Carlow has a large Brennan population only I could not access any of the information in rootsireland.Ellen came to the USA and married my ancestor Richard Roche but her parents did not come.Is it possible for you to check County Carlow for them I'm sure they had more than one child.Also would you know what county Claniss would be from if not county Carlow. The counties I have checked are Kilkenny,laois,Roscommon and Sligo.                              

Robert Roche