Searching for info on Susan Greenen born 1829 in Cavan County

I am searching for relatives of Susan Greenen, who immigrated to the U.S. during the famine. We know of her life here but nothing of where she came from or her parents, etc. Her obituary says she was from County Cavan. There is a family-told story of her voyage that says her family was wiped out during the famine and a solicitor from England came round offering passage to the states in exchange for 3 years' work. She was a teenager and local priest suggested she go. She sailed from Plymouth England. I don't know what port she was headed for, but her indentureship was in Lafayette Indiana, reportedly to work for a Colonel May. The ship's crew was drunk and they and almost all the passengers were stricken with yellow fever and died. Susan and a few other girls were lost at sea for 6-8 weeks. Eventually they washed up on the island of Cuba. They were nursed back to health and Susan was given assistance in getting to New Orleans, Louisiana, where she eventually made her way to Lafayette. She worked off her contract, married a John Martin Fitzgerald (from Galway), and raised a family. There is a bit more to her story (somewhat tragic end), but this is all I have of her origins. She was a devout Catholic and attended mass regularly in Indiana and is burried in the cemetery of St. Mary's Church. 

I was hoping to find a DNA match or news story or other detail that would help determine where she came from and who her parents were. Any help would be greatly appreciated!