The family of Home and Away star Jessica Falkholt say she is clinging to life.

Actor Jessica Falkholt is clinging to life after a fiery crash on the NSW south coast claimed the lives of her parents and sister, with her relatives now grappling with how to explain to her she’s the sole survivor.

Jessica, 28, and Annabelle, 21, were pulled from the wreckage after their car collided with a four-wheel-drive near Ulladulla on Boxing Day, killing their parents.

Annabelle was flown to Liverpool Hospital in a critical condition and died as a result of her injuries on Friday.

The driver of the four-wheel-drive, Craig Whitall, also died in the fiery crash.

“(Jessica) may wake up and, if she does wake up, is she going to be a different person?” James Randazzo, husband of Jessica’s second cousin Cathy Randazzo, told News Corp Australia on Sunday.

“If we get to that point then someone is going to have to break the news to her about the rest of her family.”

Jessica, who has played a role in TV drama Home and Away, remains in a critical condition at St George Hospital, a hospital spokeswoman told AAP on Sunday afternoon.

She has undergone several surgeries including the removal of one kidney and part of her skull and is in a coma, News Corp Australia reported.

“The neurosurgeon spoke to the family (on Friday) and said it could take weeks or months because they do not know how much brain damage there is,” Mr Randazzo said.

On Friday afternoon, the boyfriend of Annabelle Falkholt shared an emotional message saying he had lost the “love of my life”.

Jordan Brohier wrote, “the 3 years I knew her were the best years of my life. I’m so thankful for every second I got to spend with my baby”.

Image via Facebook.

"I just keep hoping that I'll wake up from this terrible nightmare and see her gorgeous eyes looking back at me.

"She was the most amazing girl I've ever met, loved by everyone that came in contact with her. Even though I would loved to have spent the rest of my life with her, I am happy that she is pain free and smiling down on all those who were lucky enough to have her in their lives."

Brohier described the last few days as "the most painful thing I've ever been through".

"You were the best thing that ever happened to me".

He ended by reminding others to be careful on the roads, where a car is a "deadly weapon".

After the crash, a cousin of Jessica and Annabelle thanked Darien Collier, the Wollongong man who pulled the women from the wreckage.

"Words can not express how grateful we are," she wrote.

Collier wrote that to describe the crash as horrific would be a "massive understatement," and said, "the injuries on the two girls will be something I won't forget in a long time".

Our thoughts are with all those affected by this tragedy.

With AAP.