An Adelaide mother has been punished enough for causing the death of her eight-year-old daughter in a fatal crash, a court has heard, with her estranged husband committing suicide one day after the crash.

Key points: Mother lost control of BMW and hit a pole

Mother lost control of BMW and hit a pole Daughter dies after suffering serious injury

Daughter dies after suffering serious injury Father commits suicide after witnessing crash

Joanne Tedesco, 33, is awaiting sentencing after pleading guilty in the Adelaide Magistrate's Court to driving without due care.

Prosecutors had earlier dropped a more serious charge of causing death by dangerous driving.

The court heard Tedesco was driving to her son's soccer match in a V8 BMW when the fatal crash happened on Findon Road at Kidman Park in Adelaide's west in April 2015.

Tedesco's estranged husband was driving behind her vehicle in a Porsche, and witnessed Tedesco accelerate quickly, lose control of the vehicle, and slam into a pole.

The woman's daughter, Nicola Tedesco, was seriously injured and died.

Tedesco's estranged husband struggled to cope with the tragedy and committed suicide the following day, the court heard.

Tedesco herself was injured in the crash and spent several weeks in hospital.

Some witnesses described the road as wet, while others said it was dry.

Tedesco's lawyer Stephen Ey said it was the first time his client had driven the BMW and the vehicle's traction control had been turned off and sport mode was turned on.

He said she was not affected by alcohol or drugs.

"She is overborne with guilt at what has happened," Mr Ey said.

He said she did not have any negative driving history other than this case.

The court heard Tedesco and her husband had been married for 10 years but were separated at the time of the crash.

Tedesco wiped away tears during the hearing.

She continues to run six Boost Juice franchises across Adelaide, including in the city and at Tea Tree Plaza.

Mr Ey told Magistrate David Whittle that Tedesco had already been punished enough and her physical and emotional scars were ongoing.

"She continues to experience difficulty in walking, plus the emotional trauma that she continues to suffer," he said.

He urged the magistrate to punish Tedesco by taking away her licence for a period of time and by imposing a fine rather than setting a prison sentence.

"It's every parent's nightmare to lose a child before you die, especially in the circumstances where you have been the cause of that death," Mr Ey said.

"She has to live with that for the rest of her life."

Prosecutor Rebecca Schell left any prison term up to the discretion of the magistrate.

Tedesco will be sentenced next Wednesday.