Rachel McAdams Received “Play Length Notes” From Judy Blume

Hollywood has been trying to adapt novels almost as long as she’s been writing them (more than 50 years). The young adult author is, rather notoriously, as reluctant to sell the rights to her work as she is adept in her storytelling — by the time she finally said yes to someone, there was an almost mythological quality to the idea of a Judy Blume film.

When signed on to , she knew all about its journey to the script stage. “I’d heard the stories of Kelly [Fremon Craig, the director] flying to Florida to meet Judy at her bookstore and court her,” McAdams says. “She kind of became our North Star as we were making this; all we really wanted was to make her happy.” McAdams plays Barbara Simon, mother to Margaret (newcomer Abby Ryder Fortson).

The coming of age tale follows the family as they relocate their rather bohemian New York City life to the suburbs of New Jersey. While the young protagonist works through the simultaneous joys and horrors of puberty, Barbara struggles to reconcile what the move means for her identity as a woman and an artist.

“It was a bit of a challenge to work out her temperature: how insecure she was about her place in the community, finding the line between being comedic and neurotic, and wanting her to be grounded but also bring a light touch to it,” says the actress. She turned to Blume for insight — the author offered “almost play length” notes, everything from imagined conversations between the parents (Margaret’s father, Herb, is played by Benny Safdie) that helped flesh out pivotal scenes, to the suggestion that though Barbara wasn’t the most fashionable person in their suburban town, she was “sexy and effortless.” McAdams is also quick to point out that though there was weight to creating this beloved adaptation after 50 years, and weight to doing it in front of the author, there was never pressure.

“She couldn’t have been more lovely or effusive,” she says of Blume. “When she came to set, she was like, ‘Oh, I’ll just sit over there, I don’t want to get kicked out.’ We were like, ‘Oh my God, are you kidding? You’re the queen! You can do whatever you want.’ ” One of the film’s most important moments comes midway through, when Barbara offers Margaret a long sought explanation for her estrangement from Margaret’s grandparents — they disowned Barbara because her marriage to a Jewish man clashed with their devout Christianity.

It required McAdams to deliver devastating lines (“They just didn’t want me in their life anymore, so I’m not”) in a manner that was tender but not traumatizing. The actress, who grew up Christian (“but not with a heavy hand at all”), related to Margaret’s big questions about God and faith but took a more analytical approach to the big scene.

“I tried to approach it the way Barbara did, which was, this isn’t a big deal,” she says. “I never felt pressure to arrive at any certain thing in my performance. It’s such a heartbreaking situation that you don’t have to manipulate it very far beyond what was there. The truth is already hanging in the air.” In the time since she worked on , McAdams has been reflecting on the fact that she didn’t read the source material until this role came across her inbox.

As a young girl, she remembers feeling as if it were taboo, something she would have had to sneak around with, despite the fact that she had the same questions about the big changes happening to her body as Margaret does. “What message was I getting that I wasn’t supposed to be reading about my period or getting breasts or liking boys?” she says.

“It’s exactly why this movie needs to be out there. When I read it as an adult, I felt sad for my younger self that I didn’t have it at the time, because I think it would have helped me feel less alone.” . THR Newsletters Sign up for THR news straight to your inbox every day More from The Hollywood Reporter.