"I just got wasted, I used ice," Wran said as her voice quivered and her cheeks turned pink.

When the daughter of former Premier Neville Wran was drifting in and out of consciousness the following day, her boyfriend of two weeks shook her awake.

Michael Lee explained that he had been watching the news and realised that the drug dealer he had stabbed and robbed ice of, had died.

"I freaked out," Wran told the NSW Supreme Court during her sentencing hearing on Thursday.

"I was so ashamed but the only way to deal with it was to keep using [ice]."

"The addiction drove me to be silent about what happened because I just wanted to get this ice."

Wran, 28, spoke for three hours in court about her struggles with bulimia and the ice addiction that led to her involvement in the fatal robbery in August, 2014.

Her frank and emotional admissions came one week after she pleaded guilty to robbery in company and accessory to murder.

The two men she was with at the time, Michael Lee and Lloyd Haines, pleaded guilty to murder in June this year.

Wran was the one who knocked on the door of McNulty's Walker Street unit, allowing Lee and Haines to rush past her and begin a violent attack.

"I feel terrible. I'm ashamed to have been involved in anything like that. I can't believe someone died. I can't believe someone was so badly hurt," Wran said after a question posed by her barrister Phillip Boulten, SC.

"I regret every step I took that night," she said. "If I hadn't knocked on the door perhaps it wouldn't have happened."

The court also heard how Wran had abused prescription drug Ritalin and dabbled in ecstasy and cocaine during her school and university years but was introduced to ice in the most tragic of circumstances.

Suffering from chronic depression, Wran checked into South Pacific Private in July 2011, an exclusive rehabilitation clinic on Sydney's north shore.

During her three week stay she met a number of ice users and became close friends with them.

After getting out of rehab, Wran went for beers with a man she had befriended and remembers being drunk when he offered her ice and she took it.

"I felt so confident; there was just a chemical high I never knew existed," she said.

"I knew the first time I took it – that it was the wrong thing to do and that I had broken a big rule in my books … and I was devastated about it when it wore off."

She spoke about how the cravings ruled her life and how she once cried all the way to a dealer's house.

"There's just a level that you reach where your head won't listen to your heart," she later said.

Under cross-examination from Crown prosecutor Peter McGrath, SC, Wran said she felt jail had saved her life.

"I think I would have killed myself [with drugs]," she said.

She also told the court that her hatred for Lee grew in the days after the murder and that she was relieved when she was arrested.

Wran told the court that when she got out of jail she wanted to study at the University of Technology, Sydney, get involved in animal welfare and eventually help others with ice addiction.

Mr Boulten argued that his client's participation in the robbery was "peripheral" and that the accessory charge was "low in the range of objective seriousness".

"Her participation was marginal, it was truncated, it was not planned, it was driven by her need for ice."

He spoke about how she had been in solitary confinement for five months in jail and that through no fault of her own, was a high profile inmate.

Wran has vowed never to touch drugs again.

"It won't happen - because somebody died and I was involved in something that led to that and I know that I won't pick up drugs again," she said.

"I never thought in a million years I'd end up in jail, let alone for murder. I've never intended for anyone to get hurt in my life."

Mr McGrath told the court he believed Wran should serve between four and five years' jail while Mr Boulten hoped his client would get out within months.

Wran has been in custody since her arrest in August 2014.

Justice Ian Harrison will sentence Wran on Tuesday, July 26.