NSW and South Australian police have linked the girl found in a suitcase in South Australia with the bones of a woman found in Belanglo State Forest.
They have identified the girl as Khandalyce Kiara Pearce and the young woman is her mother Karlie Jade Pearce-Stevenson.
South Australia Police head of Major Crime, Detective Superintendent Des Bray said both victims suffered "violent, deliberate deaths" but no family members were suspects.
"This is one of the most shocking crimes imaginable; one that has not only devastated a family, but also had a terrible impact on the wider community," he said.

The dress found with the skeletal remains of Khandalyce Kiara Pearce. Source: Facebook
"Those people that are responsible for this crime are truly evil and must be quickly caught and held to account for what they've done."
Investigators have confirmed Karlie was last seen driving a car with Khandalyce on the Stuart Highway near Cooper Pedy, NT, on Saturday November, 8, 2008.
At that time, Karlie was aged 20, and Khandalyce was aged two.
NSW Police Homicide Commander, Detective Superintendent Mick Willing, said the pair were reported missing in late 2009.

A recreation of the girl, whose bones were found in a suitcase beside a South Australian highway. (AAP) Source: AAP
“Karlie’s mum had reported them missing on September, 4, 2009, and it is understood she withdrew the report on 9 October 2009 after she was reassured Karlie was safe and well, but did not want family contact at that time,” he said.
“Police were told Karlie was sporadically in contact with her mother, but the contact became less frequent over time, and sadly, Karlie’s mum has since passed away.
“Even after this time, the extended family believed Karlie and Khandalyce were safe and well living interstate.
“As you can imagine, the girls’ family and friends are devastated. They have asked their privacy be respected at this difficult time, while they grieve the loss of two young lives.”
In July, a driver found Khandalyce's skeletal remains in a suitcase dumped on the side of the Karoonda Highway near Wynarka in the SA's southeast, which sparked an intensive investigation.
Karlie's remains were found in August 2010 and she was nicknamed ‘Angel’ by detectives as she was found with a t-shirt with a distinct ‘Angelic’ motif across the front.
Detetective Supterintendent Willing said the NSW and SA Homicide Squads are working closely to complete the picture of Karlie’s life, particularly since the birth of Khandalyce in 2006.
“We are appealing for assistance from the community to help us identify their friends and associates as they travelled throughout Australia, as well as landlords, motels, caravan parks or campsites where they stayed during this time,” he said.
“Anyone who owns or operates these businesses is urged to check their records and help us piece this puzzle together.
“We have numerous lines of inquiry to follow, and while we will do our best to keep the community informed, we need to first establish fact from fiction and ensure we avoid speculation, which could damage our investigations."
The family of Karlie and Khandalyce have issued a statement saying they were "grateful to the police, the community and media and everyone who has assisted or provided information in this investigation".
"As you would expect, our family is devastated by this news of the deaths of Karlie and Khandalyce and we are trying to deal with the grief," they said.
"We understand that this case has created considerable interest across the country but at this time we ask that you respect our privacy to allow us to grieve."
To report information about this incident contact Crime Stoppers on 1800 333 000 or visit the online reporting page: https://nsw.crimestoppers.com.au/