Homeless shelters and emergency housing centres in Auckland are at "bursting point" said Danielle Bergin, managing director for Island Child Charitable Trust.
"There are people who are desperate. There is a backlog of clients not getting houses and that's why that woman would have been in her car," she said.
"There will be more girls like that lovely girl, we hope that never happens again, but there will be more until the central housing unit at the Ministry of Social Development engage with emergency housing providers."
Bergin said a young pregnant woman arrived on her doorstep 22 weeks ago and has still not been placed in Housing New Zealand accommodation. The woman gave birth while living at the centre eight weeks ago.
She added that was also not uncommon for homeless people to be discharged from hospital with nowhere to go.
An elderly man who was discharged from hospital in December also slept in his car until he approached Island Child for help.
"In the discharge unit they need to somehow ask people if they've got somewhere to go. People who are homeless are often very proud. They've not got mental illness, they're not drug addicts," she said.
"We are now seeing a terrible wave of New Zealanders not getting the support they need and ending up homeless."