"Oh I have all that info and the manifest etc. it's really just finding Rosa Guarino's actual paper trail. "
OK, let me try this again. You state you are looking for Rosa Guarino's paper trail. Since the only documented evidence you seem to have is her name on this uncle's passenger manifest, that is where someone would begin to pick up a trail.
Can you tell us the uncle's name, manifest data, etc. so anyone who is trying to help you will have a starting point.