An interesting one. Where does your PoB of Salisbury come from? I note her DoB is from the grave.
Basically the only UK record I can find is 1901 censis in the Foundling Hospital, St. Pancras. and as a kitchen maid in 1911 to Antoinette Newton of Ladbroke Square. Both have PoB as unknown.
There appears to be no registration of the birth. Do you know when she left for Australia?