NSW mum in fatal crash's suspended licence

A young NSW mother, who was behind the wheel in a car smash that killed her two-year-old daughter and seriously injured her baby boy, was allegedly driving on a suspended learner licence.

Tori Shipman, 20, was behind the wheel on Monday night with her two children when the car rolled down an embankment on the New England Highway near Willow Tree, south of Tamworth.

Her toddler Jannali died at the scene and her 11-month-old boy Atticus is fighting for his life at Newcastle's John Hunter Hospital.

It is understood the children were returning home after visiting their father Dennis Brown in Tamworth.

"Kicking back with my daughter watching Tinkerbell and the lost treasure," Mr Brown posted on Facebook on Saturday.

"Love my baby girl always and forever."

Two days later, family and friends were plunged into mourning.

"I'm in shock and can't stop crying," friend Kathleen Head posted on Facebook.

Police say the 20-year-old mother's licence was suspended a few months ago and initial investigations indicate the girl was not secured in a safety seat.

"It was an extremely tragic and traumatic event," Detective Inspector Adam Powderly said.

"Road users need to take personal safety more seriously."

Ms Shipman, from Aberdeen in the NSW Hunter Region, remains in Tamworth Base Hospital in a stable condition where she has undergone mandatory blood tests.

The crash followed another road fatality that has torn two siblings apart, leaving a sister dead and a brother fighting for his life in the Illawarra region.

Georja Balfour was killed on Monday when the car driven by her 19-year-old brother crashed into a tree in Port Kembla, near Wollongong.

The 15-year-old died at the scene while her older brother was airlifted to St George Hospital, where he remains in a critical condition.

Police believe speed may have been a factor.

The deaths come amid a horror stretch of 11 road fatalities in four days in NSW, including a hit and run in Sydney on Tuesday.

An elderly woman was knocked over, allegedly by a taxi, while trying to cross a busy highway at Crows Nest.

Police say the driver did not stop after he hit the woman, believed to be in her 80s, and she died at the scene.

Her walking stick, a shoe and a small shopping trolley were left strewn across the Pacific Highway, according to images from Fairfax Media.