A young Whangārei woman killed on Christmas Eve after being thrown from a car as it crashed down a bank was “one of a kind”, her sister says.

Shana Homaria spent Christmas Day honouring her little sister Jacinda “Cinda” Sione-Lauaki, whose boisterous personality would “light up” every room.

The 18-year-old had been enjoying a night with friends when at around 10pm, the car she and four others were travelling in failed to make a right turn around a sharp bend on Kotata Rise in Whangārei.

Senior Constable Warren Bunn, of the police Serious Crash Unit, said the car - headed south - then veered left off the road and drove over a footpath before crashing down the bank.

Sione-Lauaki was thrown from the vehicle as it careened down the tumultuous slope.

Bunn confirmed Sione-Lauaki had been found dead under the vehicle, around 60 metres away from the road.

He was unable to say whether any others were ejected from the car. However, three other people suffered minor injuries.

A short while later, Homaria and her mum received a phone call from Sione-Lauaki’s boyfriend, Taite Kidwell.

He told them the news, their sister and daughter - and his high school sweetheart - had died.

Jacinda "Cinda" Sione-Lauaki (centre) with her "soul mate" Taite Kidwell and one of her six sisters. Photo / Supplied

“Instantly, I think, everybody was in complete shock. I never thought it would be her, out of everybody,” Homaria said.

“I was angry. We were all angry. We didn’t know what to think of it - we didn’t get time to think.”

Homaria, the eldest of 10 siblings, said she and Sione-Lauaki were close. They grew up “on each other’s tails”.

“Everything about that girl is a standout memory - you can’t pinpoint one as she was so full of life and always happy [...]

“She is beautiful in every way. She is the funniest person I know - always cracking jokes.”

The picture she painted of her sister was of a woman outgoing, outspoken and strong.

“She was always fighting for what she believed in and what she thought was right.”

But also of a person caring and generous.

“She was kind, she just loved to help everybody [...] she was always the person you could go to. She had the biggest heart.”

Sione-Lauaki, a former Tikipunga High School and Tauraroa Area School student, had just celebrated her 18th birthday in October.

She had been really motivated to start studying to become a midwife, Homaria said.

“We didn’t come from a good upbringing and she just wanted to do good for herself and lead a better life for herself.”

And a big part of those greener pastures was Kidwell, who had been with Sione-Lauaki since they met in high school.

Homaria told of how her sister called him her “soul mate” and the “love of her life”.

Sione-Lauaki was due to spend Christmas with Kidwell and her in-laws whom she loved so much, Homaria said.

While police are continuing to investigate the crash, Bunn said speed and seatbelts appeared to be an issue.

Homaria said her sister always wore her seatbelt, so she couldn’t say why she might not have at that moment.

A local Whangārei woman said the corner was a notorious blackspot.

“It just happens on the daily. You come around the corner and there’s been some kind of accident, three or four cars down the side.”

She called for action so the risk of crashes on the corner would be mitigated.

Sione-Lauaki’s death was the second road fatality nationwide this festive season and has taken Northland’s road toll to 36 for the year.

Bunn, who has seen all sorts of crashes and causes in his 42-year career, dished out some advice for motorists traversing the busy roads this holiday season.

“People do some dumb things and it can catch them out.”

He said drivers should look ahead, at least 50m to 70m in front, so they know what is coming and have time to react.

As always, stick to the speed limits and if you travelling well below the limit, pull over and let other motorists pass, Bunn added.