Jessica Falkholt is still clinging to life five days after her life support was switched off.
The Home and Away actor and her younger sister Annabelle were pulled from the fiery wreckage of their car near Ulladulla on Boxing Day but her parents Lars and Vivian died at the scene.
Annabelle, 21, died from her injuries three days after the head-on crash and Jessica has been in a critical condition in St George Hospital.
The hospital on Friday confirmed her life support had been switched off. At midday on Sunday, the hospital said she remained in a critical condition.
The driver of the 4WD that slammed into the family’s car, 50-year-old habitual traffic offender Craig Whitall, was reportedly travelling home from a Nowra methadone clinic when he was killed in the crash.
The state government says there will be a thorough investigation into the circumstances of the collision.