Lily Collins is stepping into the shoes of one of Hollywood’s most beloved icons, but the casting announcement has already sparked lively debate among fans.

Collins is set to portray legendary actress Audrey Hepburn in a new film based on the book “Fifth Avenue, 5 A.M.: Audrey Hepburn, Breakfast at Tiffany’s and the Dawn of the Modern Woman” by Sam Wasson. The project will focus on a specific moment in Hepburn’s career — the time surrounding the filming of her iconic 1961 movie Breakfast at Tiffany’s.

While the announcement excited many fans, others quickly took to social media to voice skepticism about whether anyone could truly capture the magic of the beloved star.

Amid the debate, Hepburn’s son, Sean Hepburn Ferrer, is offering a supportive perspective.

Ferrer, who authored the biography “Intimate Audrey,” shared warm words about Collins and the project in an interview with Fox News Digital.

“I love Lily Collins. Sam Wasson, the book’s writer, is a good friend of mine and I’m very happy for him,” Ferrer said. “I don’t have any huge thoughts on the film as it hasn’t been made yet.”

He also reflected on how his famously humble mother might have reacted to the film’s subtitle.

“I believe that my mother might cringe at ‘Dawn of the Modern Woman,’ but she cringed at any compliment,” Ferrer noted, adding that interest in Hepburn’s life continues to grow. “And now there are two films in prep for her, this one and ‘Dinner with Audrey.’”

Still, Ferrer admitted he’s curious how filmmakers will approach the story.

“I’m not sure how one adapts such a ‘historical snapshot,’” he said.

Online, reactions from fans have ranged from enthusiastic support to blunt criticism. Some praised Collins as “the most perfect person to play Audrey Hepburn,” while others pushed back strongly, with one commenter writing, “Dont [sic] bother love you look nothing like Audrey she was one and only and will never be replaced by you or anyone.”

Film experts say that kind of reaction is common when actors portray legendary figures.

Charlie Keil, a professor at the Cinema Studies Institute at the University of Toronto, explained that taking on such an iconic role “can be a field full of landmines.”

“When a contemporary star takes on the role of an iconic figure from the past, they may be judged by many different standards,” Keil said. “If that figure is someone like Audrey Hepburn, who has been immortalized on screen in numerous famous roles, it is a much greater challenge.”

Keil noted that Hepburn helped define an era of elegance in Hollywood.

“She was at the vanguard of fashion trends, had perfect diction, and having been born in Europe,” he said, pointing to her “distinctive and lightly accented voice.”

But Keil also emphasized that audiences don’t necessarily want an exact imitation.

“Don’t imitate — differentiate,” he said, encouraging actors to bring their own perspective when portraying famous figures.

Casting director Paul Schnee agrees that resemblance alone isn’t what makes a performance work.

“Her vague resemblance to Audrey will be an assist, but talent trumps that,” Schnee said, adding that the most important factor is whether the actor can capture the “essence of the person.”

For Collins, the role represents a long-awaited opportunity. The actress revealed that the project has been in development for nearly a decade.

“It’s with almost 10 years of development and a lifetime of admiration and adoration for Audrey that I’m finally able to share this,” Collins wrote on Instagram after the announcement. “Honored and ecstatic don’t begin to express how I feel.”

As the film continues to take shape, one thing is already clear: portraying Audrey Hepburn remains both a tremendous honor — and a tremendous challenge.