Herald inquiries have also revealed that the family wrote to Health Minister Jonathan Coleman last October asking for help and improvements to adolescent mental health care six months before the girl climbed onto a bridge over the motorway.
Coleman's response to the family, sent to the Herald, showed he made contact with the Auckland District Health Board to make sure they were aware of concerns for the girl's wellbeing.
The girl's aunt, who took over as her primary caregiver two years ago after the pressures overwhelmed her separated parents, said staff at ADHB knew her niece was unwell when she was absconded on Friday.
When the aunt rang the night before, she was told the girl was "not in a good head space".
"She's there because they're meant to be keeping her safe. I said 'what was she doing out?'."
The aunt said the girl had always been a bright, intelligent child who came under severe pressure a few years ago through online bullying.
"That was when we started noticing the changes in personality."
The girl started to self-harm and the family began seeking help, with her eventually spending time in adolescent mental health units.
"There don't seem to be the services out there to manage them," she said.
"In the first year, they kept putting her back on family and couldn't understand when we said we couldn't keep her safe."
The aunt said there also seemed to be no coherent care plan as the girl went between several hospitals.
"She's never been in one place long enough to receive constant care."
The aunt had high praise of Child Youth and Family which they sought out after realising they could not deal with the child alone. It was helping find support for the teen.
A spokeswoman for ADHB said an investigation would be carried out into the incident and a copy of the inquiry report provided to the Ministry of Health.
The spokeswoman said it had short-term in-patient care for young people with acute mental health services but it's aim was "to have young people back with their family or whanau as soon as is appropriate".
The Ministry of Health was asked whether it considered it currently met the mental health care needs of adolescents but did not answer the question.
Instead, an emailed response gave details of programmes currently available and said it was currently seeking views from the public on suicide prevention strategies.
Coleman also did not respond to questions over whether adolescent mental health needs were being met.
He said the girl's situation was "an incredibly complex case" but was "fully resourced". He said "discussion through the media of the particulars of the case is not actually in the patient's best interest".
Children's Commissioner Judge Andrew Becroft - who has been advised on mental health issues - said there appeared to be mental health need among adolescents that wasn't being met.
He said he had been advised there had been an increase in need which had placed greater burden on NGOs providing much of the mental health support services available.
"The current significant increase in demand has exposed that hole that will need to be filled pretty quickly.
"It seems there have been resourcing issues that have been raised by an increase in demand."
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (Mon-Fri 1pm to 10pm. Sat-Sun 3pm-10pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.
