I don't have a Costello in NYC that I know of, but my great grandmother, Catherine Green emigrated about 1867. Her mariage license showed her mother to be Marie Costello and her father Michael Green. Catherine was about 11 or 12 years old when she came from Ireland. One of the witnesses on her license was Bridget Green, who I hope was a sister. I don't know if she came with her parents or not. I haven't a clue where in Ireland she came from. She married James McCaffrey in 1876 in NYC. He also came from Ireland about 1870. The big question would be, did she come with her parents or did children that young emigrate at that young age back then. Any thoughts? Marilyn