I know from my great grandmother Mary M. Donahue's marriage certificate that her parents were Patrick Donahue and Jennie Gibson, and census data list them as born in Ireland. Mary was born in NY around 1869. She was living in an orphanage with her sister Alice in 1880. I have no other information. Can anyone help me as to where to start on the Irish trail? Does it seem that DNA is going to be the only way to go? Thanks in advance.