Jessica Falkholt's life support has reportedly been switched off after horror crash.

Home and Away actress Jessica Falkholt remains in a critical condition in a Sydney hospital with reports her life support was switched off overnight, more than a fortnight after a horror crash that killed her parents and younger sister.

The 28-year-old has been fighting for her life in St George Hospital since she was pulled from the wreckage, along with her sister Annabelle, 21, on December 26 near Ulladulla.

She remains in a critical condition, a spokeswoman for St George Hospital told AAP on Friday.

Falkholt’s family were laid to rest after a funeral at St Mary’s Catholic Church in Concord on Wednesday.

Jessica’s life support was turned off a day later on Thursday night, according to media reports.

The Falkholt's family car was hit by a four-wheel drive, incinerating both vehicles, and parents Lars and Vivian died at the scene on Boxing Day.

Annabelle died as a result of her injuries three days after the smash.

Following report's Jessica's life support had been turned off, a tweet was sent from TV show, Home and Away, on which she had her break-out role: "Rest in peace, beautiful Jessica Falkholt".

The driver of the four-wheel-drive, 50-year-old Craig Whitall, was reportedly travelling home from a Nowra methadone clinic when he was also killed in the collision.

Whitall was a habitual traffic offender with more than 60 convictions to his name, according to The Daily Telegraph.

Lars and Vivian and their daughter, Annabelle, were farewelled by hundreds of family members and friends at St Mary’s Catholic Church, Concord, before a private internment.

Photographs taken at the ceremony show mourners clad in black, huddled around three hearses. In each, a coffin adorned with roses and lilies – pink for the 21-year-old, white for her parents.