19th century Flood family

Greetings from the U.S. We are researching my husband's Irish ancestry. His 2nd great-grandmother was named Mary Flood. Her father, Mathew Flood  was born (we think) around 1812 and her mother, Hanora Brazil around 1814. Mary, born in 1840 came to New Jersey before 1866, which is the year she married into the family here. We have no evidence to suggest that her parents ever left Ireland. Mary Flood is believed to have been born in Pallasgreen, Limerick. Any information that comes up about this family would be very much appreciated.