A driver who was texting behind the wheel in the moments before a crash that killed her friend has been found guilty of aggravated dangerous driving causing death.

Aine McGrath, 26, was driving a Mitsubishi Lancer on August 14, 2016, when it veered across four northbound lanes of Mitchell Freeway near Leederville before being T-boned by a Holden Colorado.

The utility slammed into the passenger side of the car, fatally injuring McGrath’s 25-year-old friend and colleague Sarah Kelly, who died at the scene.

McGrath this week faced trial in the District Court for a second time over the fatal crash after the jury in her first trial in February was discharged when it could not reach a verdict.

Camera Icon The crash occurred when a Silver Mitsubishi Lancer travelled at nearly 90 degrees across the Mitchell Freeway from the right hand lane eventually colliding with a Holden Colorado that was travelling in the left hand lane. Credit: WA Court

Prosecutors alleged McGrath was distracted by her mobile phone, driving too fast, or both.

McGrath admitted she had previously been texting her boyfriend while driving but claimed she did not read the last message that was sent to her phone in the crucial seconds before the crash.

She said a car had pulled in front of her as she tried to change lanes and she lost control when she swerved to avoid hitting it.

However, after deliberating for more than three hours, a jury rejected her account and convicted her of dangerous driving causing death in circumstances of aggravation.

During the trial, the jury were shown a text exchange between McGrath and her boyfriend in the ten minutes before the fatal collision.

The last text was received at 16.16.49 – about 12 seconds before the first triple-0 call was made.

Camera Icon Sarah Kelly, 25, died in the 2016 crash. Credit: Supplied

Witness Jennifer Lennon, 58, testified that she saw McGrath’s car “coming up very quickly” behind her so she changed lanes.

Ms Lennon said after she changed lanes, she looked in her rear view mirror and saw the car swerving.

Kate Matthews, 36, told the jury she was driving her Holden Colorado, with her husband and twin boys, who were aged five at the time, in the passenger seats.

Ms Matthews fought back tears as she described having to slam on the breaks and hold onto the steering wheel.

“There was nothing much I could do,” she said. “We just crashed into the car … straight into the passenger door.”

Judge Stephen Scott granted McGrath bail but told her she "must not think that's any indication of my sentencing disposition", adding she had been convicted of a "very serious" offence.

Prosecutor Ben Stanwix flagged the State would be asking for an immediate jail term. he also asked for McGrath's licence to be revoked as part of her bail conditions, saying it would be "inappropriate" for her to be "at liberty to drive".

Judge Scott said he did not think it was necessary to ban her from driving before she is sentenced on October 18.

McGrath broke down in tears when the verdict was delivered.

- With AAP