The mother of the youngest victims of this week's horrific crash in South Taranaki remains critically ill in hospital today.

Ani Nohinohi is the only person to survive the two-car crash in Waverley on Wednesday that left seven dead; including young sisters Nivek Madams, 8, and 8-week-old Shady Thompson.

A spokesman for Wellington Hospital, where Nohinohi was airlifted to that fateful day, confirmed she remained in a critical condition in the hospital's intensive care unit.

It is understood the young mother - who also lost her partner Jeremy Thompson, 28 - in the crash, does not yet know of the deaths.

Funeral arrangements are not yet known for the Madams and Thompson whanau, but members of the public have been quick to help with funeral costs for youngest victims, Nivek and Shady.

A Givealittle page set up by loved ones had raised almost $8500 by this afternoon.

"Nivek & Shady were close sisters and part of a caring whanau - deeply loved by their friends & family,'' the page reads.

"Their tragic passing has been devastating for everyone and we are grateful for the outpouring of support from the community.

"As the new cluster of Matariki stars for those who have left us were announced, these little lives sadly slid away.''

Nivek's godmother, Joy Clark, is associated with the fundraising effort and all funds would go directly to the whanau for costs associated with the girls' funeral services and headstones at a later stage.

As well as Thompson and the two girls, four elderly people travelling in the second vehicle were all killed instantly in the crash.

Husband and wife Ian and Rosalie Porteous, aged 80 and 74 respectively, Ian's sister Ora Keene, 84, and her friend Brenda Williams, 79, were named as the victims.

A family notice today paid tribute to Ian and Rosalie; dearly loved mum and dad to Len and Shelley, Craig, Logan and Anna.

They were also grandparents to eight and great-grandparents to Carter and Lincoln.

The family also gave a message of thanks to those who were first on the scene: "A special thank you to all the emergency services for their help and support.''