Kristen Stewart Reveals Her One Regret About Playing Princess Diana in New Film

Kimberly White/Getty Images; Tim Graham Photo Library via Getty Images Kristen Stewart; Princess Diana

Kristen Stewart is already getting Oscar buzz for her portrayal of Princess Diana in Pablo Larraín's biopic Spencer, but there was one important element where the actress wasn't able to fully connect with her character.

Stewart is playing an anguished Diana as she joins the royal family for the Christmas holiday in 1991 — and at 31 years old, the actress is only one year older than Diana was at the time of the film. However, she told The Daily Mail that she regretted that "I'm not a mum yet."

"It's the one part of playing her that I felt disloyal about," Stewart said.

Princess Diana's sons, Prince William and Prince Harry, are featured in the movie. They were 15 and 12, respectively, when their mother died in a Paris car crash in 1997.

Stewart spent extra time with the actors who played her sons (Jack Nielsen as Prince William and Freddie Spry as Prince Harry) on set as she said the film's director wanted the mother and sons to be like "a three-headed animal in a bubble."

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Stewart believes Princess Diana was most "untouchable" when she was with her two young sons.

"She's like this feral animal you wouldn't dare accost," the Twilight star said.

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And that wasn't the first time Stewart referred to Princess Diana as "feral." Speaking with the the Los Angeles Times, she said, "Any picture or interview I've ever seen of her, there's an explosive, ground-shaking quality to her that I always feel like you never really know what's going to happen. Even when she's walking the red carpet, it just feels a little bit scary. That could be projection, because we all know what happened. But she just has this feral cat feel. So I wanted to convey that. There's no way to plan chaos. You just have to fall into it."

Stewart has also likened the princess to a beloved icon from children's television.

"It would've been easy to make her kind of perfect and it's so fun to martyr her because she's beautiful and just wanted people to be happy. She's like Mister Rogers," she said during a seminar at Telluride Film Festival. "There are certain people where you're like, 'Are you that sincere? You're making me uncomfortable!' I was opened up by her in a way that was so striking."

Stewart also noted that Diana was "a huge contradiction, the weirdest combination of things that don't necessarily go together all the time."