Who is Rachelle Louise? The 25-year-old former girlfriend of convicted murderer Simon Gittany is suing Nationwide News, the publisher of The Daily Telegraph, over three stories that allegedly made her out to be a prostitute, a stripper, a bimbo, and a "woman of loose morals".

The defamation case in the NSW District Court has revealed the background of the woman who stood by Gittany during his 2013 trial, which led to a conviction for the murder of Lisa Cecilia Harnum, whom he threw from a 15th-storey balcony.

Ms Louise told the court on Tuesday that she and Gittany remain friends, but are no longer romantically involved.

"I see him almost every weekend, we keep in contact every day," Ms Louise told the court, after saying she believed he is innocent.

"I think it's very difficult to sustain a relationship with someone who is in jail."

Ms Louise said Gittany, who is serving a minimum 18 years' jail, was appealing, and it was best to remain just friends until "we know more about the situation".

The couple met when Ms Louise was 19, through a mutual friend, and they became a couple when Gittany was facing the murder charge, she said.

The court heard Ms Louise gave Gittany about $85,000 of her life savings to fund his defence, and borrowed $35,000 from friends.

Her mother and father also gave Gittany thousands of dollars for legal costs, she said.

Before meeting Gittany, Ms Louise said she graduated from Rosebank College, in Five Dock, and went into a highly paid IT project management role at the Commonwealth Bank.

Ms Louise legally changed her name from Rachelle Louise Welcome after a relationship with a bank colleague ended "unhappily".

"I changed it, just to start fresh," she said.

She said she saved up $60,000 to travel the world, and denied she ever worked as a stripper in Las Vegas, or a masseuse in London, as reported by the Telegraph.

Upon her return to Australia, Ms Louise got a role as an extra in one of the Underbelly series on Channel Nine, through a casting director friend.

She said she is now studying law in the hopes of becoming a criminal barrister, and does paralegal work in chambers in Sydney.

The court heard she worked on Gittany's case by reading police statements, and has since tracked down witnesses and CCTV footage.

Ms Louise said she was upset and hurt by The Daily Telegraph articles, two of which were written by police reporter Clementine Cuneo.

"I was upset because she was ... basically calling me a whore," she said.

Nationwide News is claiming truth in defence of many of the allegations made against it and also argues that other comments are simply expressions of opinions and not stating a fact.

The trial continues before Judge Judith Gibson.