Gardaí have identified the female who was discovered on O'Connell Street in Dublin last month.
In a statement, gardaí said they are following a definite line of inquiry.
They are liaising closely with the Australian police and the Health Service Executive to "finalise the matter".
The Australian Federal Police confirmed it received a request for assistance from Irish authorities through Interpol.
"The AFP, in conjunction with appropriate state police forces, are assisting Irish authorities with this request," said a spokesman.
"As this matter is ongoing, it is not appropriate for the AFP to comment any further."
A photograph of the girl, who was found in a distressed state in Dublin city centre last month, was released yesterday by gardaí.
Superintendent David Taylor said Operation Shepherd, the garda investigation following the discovery of the girl, has involved over 2,000 man-hours and over 115 lines of inquiry.
Gardaí had sought the assistance of the Missing Persons Bureau, Interpol, the Domestic Violence and Sexual Assault Unit and the Garda National Immigration Bureau among others.
They had carried out door-to-door inquiries, viewed CCTV footage from the city centre and checked the missing persons' list.
They also canvassed ports, airports and train stations with images of the girl.
B&Bs and guesthouses in the city centre were checked for people who booked and did not turn up, or for people who stayed and did not return.
Gardaí checked left luggage storage services in the city centre for uncollected luggage and for property that was past its pre-paid date.
Paediatric orthodontists nationwide were also canvassed, as the girl has a brace.