We started with Ann Jane Radcliffe's marriage:
Marriage 21 July 1860: Robert Bannon laborer Andreas, father Robert Bannon, shoemaker & Ann Radcliffe Andreas, father John Radcliffe farmer.
Witnessed by John James Radcliffe. [Witness was Ann Jane’s eldest brother.]

From censuses we thought that his parents were Robert Bannon & Elizabeth Corlett who marr. 22 May 1838 in Lezayre (as Frances wrote), and that father Robert was bapt 25 April 1813 Andreas, son of Thomas Bannan and his second wife Cath Christian.

Then in April 2007 Emile Franco wrote on the BB "I am descended from Thomas Bannan, who had at least eight children with Catharine Lennaghan before 1798, and at least six children with his second wife Catharine Christian.
I am descended from Thomas, son of Thomas Bannan and Catharine Lennaghan......
"..an initial thought is that they must have come from Ireland. I do know from Catharine's probate record that she had a brother John".
(There is more of his message in the BB archives - use Search.)

I suggested RC records for Catharine Lennaghan, but I don't know whether he followed this up. If you put RC records as a subject heading, you may attract the attention of a BB user who has transcripts of these.

We didn't look for Catherine Christian, but I'll have a look tomorrow (night-time here).

Sue