Crash unit Senior Constable Warren Bunn said Sione-Lauaki was thrown from the car as it careened down the slope and was found dead under the vehicle, around 60 metres from the road.
He was unable to say whether any others were ejected from the car. However, three other people suffered minor injuries.
Shana Homaria spent Christmas Day honouring her little sister whose boisterous personality would “light up” every room.
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.”
Homaria also noted her sister’s caring, generous side.
Last night’s death took Northland’s road toll to 37 for the year.