Patrick Nolan Lower Manor

My great grandmother was Ellen Nolan from Lower Manor who married Hugh Hennigan from Rathmore on 6 February 1866. I know from the Marriage Cert Ellen's Father was Patrick and Hugh's was Thomas and it appears they were both alive at that time , how can I find out who my gg grandmothers were? I cannot find either the death of Patrick Nolan or Thomas Hennigan.I would appreciate anyy information.

Kind Regards

Unad