Elizabeth Anne Quill, of Lalla, has been charged over the death of Jayden John Pearce, who died four days after the crash on Pipers River Road. Ms Quill was also charged with driving under the influence of drugs, having admitted to using ice the day before the crash.

She has pleaded not guilty, and the second day of the hearing into the matter was held in the Launceston Magistrates Court on Wednesday.

During the first day of the hearing on Tuesday, the court heard from Jackson Spratt, the best friend of Mr Pearce, and driver of the other vehicle involved in the crash.

Mr Spratt told the court he was driving down Pipers River Road when he saw Ms Quill's Ford Laser coming toward him in his lane, and when she did not go back into the correct lane he swerved to avoid a crash.

As a result, the passenger sides of each car collided.

Defence lawyer Alan Hensley had argued Mr Spratt was distracted and was travelling at excessive speed, then lost control after hitting the dirt on the side of the highway.

But three crash investigators who took the stand throughout the two-day hearing each told the court there was no evidence either vehicle left the road.

Veteran crash investigator First Class Constable Nigel Housego said from looking at photos of the scene, his experience told him it was not a high-speed crash.

"I have been to over 300 crashes, I'm pretty comfortable that neither car was travelling at high speed," he told the court on Wednesday.

"Nobody in those cars would have survived at high speed ... they are old cars, their safety features are rubbish."

Despite the crash investigations finding Ms Quill had been in the wrong lane at the time of the crash, Mr Hensley continued to suggest a different scenario.

He again suggested to Senior Constable Michael Rybka, another experienced investigator who had attended at least 85 fatal crashes, that it was Mr Spratt who lost control of his vehicle before the crash.

However, Senior Constable Rybka said the marks left on the road by Mr Spratt's Kia Rio told another story.

"It is my opinion that the driver of the Kia Rio has been conscious, he has been alert, and he has taken evasive action in the form of steering to the right ... steering away from an oncoming vehicle," he told the court.

"It is quite simple, the Ford was on the incorrect side, the Kia was on the correct side, and tried to avoid impact, but couldn't."

Ms Quill did not give evidence in the hearing.

Magistrate Simon Brown adjourned the matter until June 1 when he will hand down his decision.