Hi again Robyn
Not being rude but are you 100% certain that you have the right certificates for the right people??
I found an ANDERSON and MCCARTHY birth.
Given name Edith Ellen
Father John Balfour ANDERSON
Mother Edith Sarah PARTRIDGE
Birth place/residence Norwood
Given name Edith HELEN
Father John MCCARTHY
Mother Elizabeth LEWIS
Birth place/residence St Anthony St
Maybe you could post on the South Australian board, there are lot's of people on there happy to do lookups. But just make sure that you post everything that you already know so that people aren't doubling up research. I will see if I can find a marriage for Edith Mccarthy.