Home and Away actress' sister Annabelle Falkholt dies in hospital after crash

Annabelle Falkholt, the sister of Home and Away actress Jessica, has died in hospital three days after their parents were killed in a horrific NSW south coast collision.

Ms Falkholt, 21, was a passenger in her parents' car when it collided with another car on Boxing Day, on the Princes Highway, north of the Bendalong turnoff.

Actress Jessica Falkholt, 28, who was also a passenger in the car, remains in a critical condition in Sydney's St George Hospital.

Witnesses pulled the girls from the wreckage as the vehicles were engulfed in flames.

The crash claimed both their parents, Lars Falkholt, 69, and Vivian Falkholt, 60, who died at the scene near Sussex Inlet.

The man behind the wheel of the other car, Craig Anthony Whitall, 50, was also killed when the vehicle crossed into the path of oncoming traffic.

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Mr Whitall's family have spoken out on the tragedy saying their "hearts are broken" not only for their loss but "also for the loss the Falkholt family are feeling".

Earlier on Friday, Mr Whitall's son and mother spoke to Seven News about the tragedy.

"He did the best he could and you couldn't ask anymore of him," his son Shane said.

"That's all you can ask of anyone, to do the best they can."

His mother Trish said she is hurt that people are talking badly about her son. He has been described as a serial driving offender and drug user in reports following the Boxing Day tragedy.

"He was very private and didn't like people talking about him but the worst part is, he has grandkids that can read, that are listening to it," she said.