Thomas O'Brien lived with his wife, Nellie Fitzgerald, in Mitchelstown, Cork, when they had their daughters, Mary Brien b1833, Ellen Brien b.1835 and Catherine Brien b.1836. I don't know if they always live there. I'd like them to connect to Edward O'Brien born abt 1845 to parents of the same name. But the girls are the only trace I can find of Thomas and Nellie.