Don't know. Just going of what I read.
I guess there was no doubt Tegan had been born - when, where and how - all known.
The mothers name, age, address, occupation all known. Tegan had been recorded on Medicare records by her mother. She was still carrying the card in her wallet.
Father - Well I guess imo, it is who ever the mother says it is. Unless dna proves otherwise.
Nice Girl: The story of Keli Lane and her missing baby Tegan
https://books.google.com.au/books?isbn=0731814975
Rachael Jane Chin - 2011 - True Crime
The story of Keli Lane and her missing baby Tegan Rachael Jane Chin ...
There wasn't even a birth certificate for Tegan until Abernethy ordered one for her in 2005...