Peter Matthew Riley and Ellenor Brennan

These were the parents of Brigid Riley who emigrated from Ireland and settled in New South Wales in 1838.  She was my ggg grandmother.  I know that Ellenor was born in Lurgan Cavan in 1793 and that Peter was born in Cavan (don't know whether or not in Lurgan) around the same time.   I'd love to keep going back. 

Also so can someone tell me if they would would have been likely to speak Gaelic instead of, or as well as English.

thanks for any help you can give me