Ellen would have sailed from Cork, the ship records always state the port where it first leaves from.
I looked in the Tithe records 1823 to 1837 and the nearest Thomas Carew to Caher or Cahir is this one. (Same place)
Searching again in the Griffiths Valuation records 1847 to 1864 I saw this, listed under the Union of Cashel (different records record different areas)
In the same townland of Knockgraffon.
Note the land lord was Robert Carew. This Robert, his parents were Lord and Lady Carew ( they didn't have a child called Thomas)
The next place to look for Ellen's Baptism is...........the link is the main web address.
This is the Caher Parish Book. (a bit hard on the old eyes)
Parish's also overlap in records.
I had a quick look and found a death of a Lady Jane Carew she died in 1901.
I hope this is a help.