Wilson's directorial debut The Deb, which premiered at the festival two years ago, was embroiled in legal disputes, delaying the film's release in theatres.
In July, a Sydney court cleared Wilson of defaming The Deb's lead actor Charlotte MacInnes, who was appealing.
"I was so happy to have a court rule overwhelmingly in my favour earlier this year. And I feel like The Deb did have a setback because of the litigation that was brought by the other producers," the Australian told Reuters in an interview on Saturday.
"I, for the most part, kept my head down, worked on Girl Group in the meantime and just had such a sensational, fun experience on that."
A separate lawsuit was filed against Wilson by The Deb producers in a US court.
Her new musical comedy follows the story of a disgraced pop star who was excluded from her former girl group's reunion tour and has to mentor a group of young girls under a community-service sentence.
Girl Group is a full-on celebration of girl group music from throughout like the past five decades," said Wilson, who plays the lead while also directing, writing and producing the film.
"It's a story about friendship, about working together to create something great."
The film features real girl group legends, including Spice Girls' Melanie Chisholm, All Saints' Shaznay Lewis and Pussycat Dolls' Ashley Roberts and Nicole Scherzinger.
Wilson said that her film was once rejected by a studio because it was a "female-driven" film.
"I was shocked by that because I've been in these female-driven ensemble movies that were absolutely huge and made hundreds of millions of dollars," said Wilson, who starred in Bridesmaids and the Pitch Perfect series.
