Faith's Tauranga-based grandmother Ipu Leaso told the Herald on Sunday the Australian authorities should have checked that Faith arrived in New Zealand and was attending school.
"That is their duty to do that. That is why these things happen because things are not checked," Ipu told the Herald on Sunday yesterday.
"They should have made sure she came here."
But the checks weren't made.
Authorities stopped monitoring Faith because she was leaving Australian but no checks were made to confirm the family had returned to New Zealand.
This was despite an arrangement between New Zealand and Australia called "The Protocol for the Transfer of Care and Protection Order" which allows reports of concern and alerts to be sent between New Zealand and Australia as part of the care and protection of children and young people.
Child Youth and Family Services spokesperson Amanda Forsey would not comment saying it was an Australian case that New Zealand authorities had no involvement in.
Ipu and her husband Paulo Leaso were unaware their daughter had told authorities she was moving back to New Zealand.
"We wish we had of brought Faith back here with us when we visited her. She was a lovely girl, we loved her and think about her all of the time," a tearful Ipu said.
"Just this morning we talk about her."
The heartbreaking case highlights failures within the Australian child safety network, Queensland coroner Jane Bentley said.
She said communication breakdowns between state and federal departments, as well as external agencies, were a significant factor in Faith's death.
Bentley recommended changes aimed at preventing other children from "slipping through the cracks", including setting up an information-sharing system to give schools and other child agencies access to basic Centrelink data.
Last year Ane Leaso, now 30, was jailed for seven years for manslaughter, while the girl's stepfather was also convicted on manslaughter charges for ignoring the abuse.