Anong Luk, 24, also known as Gol, died after she was dragged by a moving car and was pinned between two vehicles in Melbourne's west in November last year.
Police say her 22-year-old sister Asyai Luk was behind the wheel of the moving car following a roadside argument and she fled from the scene.
Luk faced a committal hearing in Melbourne Magistrates Court on Monday, supported by their mother Aleza Gwit.
She is charged with dangerous driving causing death, and failure to stop and render assistance.
She was not required to speak during the hearing.
Her barrister Peter Morrissey said he believed the matter should be discharged, as the incident was a "freakish occurrence" that neither sister could have foreseen.
He said his client drove away from the scene, worried what her sister might do if she got back in the car, following an earlier physical altercation.
"The way the sister was trapped, was tragically unusual and unlikely ... She got caught in the door unexpectedly," Mr Morrissey told the court.
"And CCTV footage shows that she drove forward and was looking forward - not in anyway towards or at the peril of the deceased.
"She didn't know the accident had occurred."
The prosecution disputed Mr Morrissey's claims that Luk was not driving dangerously.
"In the context of a heated argument that was both verbal and physical between the two sisters, Ms Luk drives off with the door wide open and at a fast rate of speed," prosecutor Abbey Hogan said.
"Gol Luk walks out, places her arm on the door and goes to put her foot in the car and that's when the accused takes off at speed, with the car door open.
"It is plainly dangerous to drive off at speed with a car door open."
Magistrate Brett Sonnet reserved his decision for Tuesday morning.
10°C