The Pitch Perfect star is being sued by Charlotte MacInnes, the 27-year-old lead actor of the musical comedy The Deb.
MacInnes claims she was defamed by Wilson in social media posts that suggested she is a liar who retracted a sexual harassment complaint to further her acting and music career.
As Wilson entered the Federal Court on Wednesday, she said she was preoccupied with the impending birth of her second child.
"If I seem a bit anxious, it's because any day my second child may be born, hopefully not today," she told reporters.
The Bridesmaids star said she was unable to comment about the case out of respect for the legal process, but thanked the cast and crew of The Deb for their continuing support.
She went into the witness box for a second day after she repeatedly rejected accusations she was lying while being grilled under cross-examination on Tuesday.
Wilson claims MacInnes confided that she felt uncomfortable after the film's co-producer Amanda Ghost asked her to have a shower and a bath together in September 2023.
"I was pretty shocked by it," Wilson told the court on Tuesday.
"I took it as a sexual harassment complaint."
Work had been under way on The Deb for years and shooting was weeks away at the time, the actor told the court.
"This is a fun girl-power movie and the worst thing that could have fallen into my lap at that point was a sexual harassment complaint," she said.
The conversation allegedly occurred a day after MacInnes shared a bath with Ms Ghost in their swimwear in a bid to warm up after the producer suffered a medical episode at Bondi Beach.
MacInnes denies making a complaint to Wilson and insists she never said she felt uncomfortable.
Wilson said she asked the young actor if she was alright and reported the matter to another producer before escalating the issue at a later date.
She is expected to be grilled about the aftermath of the alleged complaint as her evidence continues.
In her affidavit, the first-time director wrote that she overheard the producer and young star saying things of a sexual nature to each other, which MacInnes has rejected as false.
It is likely Wilson will face questioning about a claim MacInnes made in her own sworn statement that the older actor had directed a cyber attack on her social media accounts.
MacInnes alleges her Snapchat account was breached and there was an attempted breach of her Facebook account days after she filed legal proceedings against Wilson in September.
The hack led to a nude photo of her being leaked to all of her contacts, she claims.
"I believe that this was orchestrated by Rebel," she wrote in her affidavit.
There has not yet been evidence aired in open court to support her claim and Wilson is yet to be asked about it.
