Catherine "Kate" Carty (1850-1935)

I am searching for the family of Catherine "Kate" Carty (1850-1935). She was my great grandmother. She emigrated to America around 1865 at the age of 16.She married my great grandfather Nicholas "John" Joseph Lynch of Lynchfort House, Loughrea. I found all the information on the Lynch family, but I hit a wall with the Carty family. The family story is that Kate was a servant at Lynchfort House.They landed in Philadelphia, lived in New Jersey for a number of years and bought a farm in Chester County, PA. I think they were married after they arrived in America. I can not find any ships list for John and Kete. I have been to Loughrea many times and have friends there. The people of Loughrea have been very welcoming. If anyone can help me solve the "Carty" mystery, I would be very thankful.