Questioned by police after the incident, Karen Lee Codey admitted she was the driver at the time and said: "I would've got out of the car and punched the rock spider".

The 54-year-old then stated a man's name, who police could not disclose.

"He snitched on .... if I didn't kill him running him off the road, I was going to get out of the car and bash the s*** out of him with a baseball bat," she said.

Police informed Codey she had wrongfully assumed that the car was driven by the man. She was told the driver was an "innocent" young woman.

"Oh okay. Well I f***** up then hey. Tell the driver I apologise and I will cop whatever is coming," was her response.

Read more: South Coast mother convicted for hiding husband's sexual abuse

At Milton Local Court on Thursday, Codey pleaded guilty to a predatory driving charge.

The court was told victim of the unprovoked attack felt threatened, intimidated and shocked and was "extremely distraught" after the incident.

According to police facts tendered to the court, Codey's victim left Tomerong on March 9 to drive to Mollymook with her mother.

The victim drove past the overtaking section south of the Sussex Inlet turn-off when she noticed a dark coloured sedan approaching fast behind her.

Codey travelled behind the victim's car "at a very close proximity" to the point that the victim could not see the front lights of Codey's sedan.

For the next 10km, Codey tailgated the victim's car. At the overtaking lane north of the Bendalong turn-off the victim activated her left-blinker and entered the slow lane.

Codey "immediately" accelerated and overtook the victim and then continued to drive in the second lane. She then veered left into the left-lane causing the victim to "abruptly" slam her brakes.

The victim was frightened and concerned for her and her mother's safety as it appeared the accused was "intentionally attempting" to intimidate her.

Codey then re-entered the overtaking lane and slowed down drive alongside the victim, preventing her from merging to the right. The victim accelerated to pass Codey and got in front of her.

Codey began to tailgate again before she veered into the northbound lane, crossing unbroken lines. She then drove alongside the victim while she was on the opposite side of the road.

Codey then "swerved sharply" to the left and entered the southbound lane in front of the victim. The victim "stepped harshly" on her brakes and swerved to the left, causing her car to leave the road way on the eastern shoulder of the Princes Highway.

Magistrate Michael Stoddart imprisoned Codey for 12 months with a non-parole period of nine months.

Codey will appeal the severity of the sentence at Nowra District Court on August 5.