What this source establishes
A scholar of South Indian religion, working from the Jesuit manuscripts at the Madura Mission Archives rather than from anything the parish published, who records a woman founder and a small shrine containing a cross — and who goes further than the parish does: she calls her the actual founder of the village, and identifies her as a Shanar (Nadar) woman, a charismatic Christian teacher. The page tells the story without her caste, because the shrine does not tell its history through caste; the book says what it says, and here it is. We do not hold the volume — this is quoted at second hand, and it is still in copyright.
This is as much of the book as this site prints. It is named in full in the bibliography below.