Get in, loser. We’re riding with Rachel McAdams because she’s still Queen Bee.

Since she’s become a mother, life has changed. During the filming of Lionsgate’s “Are You There God? It’s Me, Margaret” she had her five-month-old daughter and two-year-old son on set. Even her younger sister and make-up artist Kayleen had her two children, two and three months, by her side. “We had a really amazing mom-positive set,” she tells Variety. “Everyone understood me having to send breast milk down the road in a van all day long.”

But McAdams is susceptible to the looming sense of “mom guilt” that plagues many working parents, despite being “very lucky” to have lots of time with her kids. She found that connection and applied it to portray her role as Barbara Simon, the mother of the titular character Margaret (played by Abby Ryder Fortson) in Kelly Fremon Craig’s adaptation of the beloved Judy Blume book that had a 50-year journey to make it to the big screen.

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While preparing for the role, McAdams says there were multiple conversations between Blume and Fremon Craig about how they wanted Barbara to be portrayed. “We had a lot of conversations about making our film relatable and klutzy at times,” she recalls. “I had Judy on one hand saying, ‘I think she should be sexy. Why can’t moms be super sexy?’ And on the other hand, Kelly asking me, ‘Do you think you’re a super sexy mom?’ And I was like, ‘No, do you feel like a super sexy mom?’ And she said, ‘No, but we are. We just don’t feel like it.’ It was finding the middle ground where we can be all these things, and there’s honesty in that.”

Dana Hawley/Lionsgate

The movie has generated universal acclaim, with many citing McAdams’ impressive turn. Already snagging a massive win from the L.A. Film Critics for best supporting performance and other regional critics groups, she’s within arm’s reach of securing her second Academy Award nomination following “Spotlight” (2015). Fremon Craig also snagged an adapted screenplay nom from the Critics Choice Awards, and with Oscar winners attached like actress Kathy Bates and producer James L. Brooks, the film is even a dark horse for best picture attention.

It follows an 11-year-old girl in 1970 navigating the confusing times of puberty and adolescence and is a beautiful portrait of womanhood. It feels like the cinematic brainchild of “My Girl” meets “The Sandlot,” the classic throwback to the family films of the ’80s and ’90s. It’s not often we see a film depicting the journey of a girl’s first menstrual cycle with such earnest sincerity.

As a father of a 12-year-old girl, it’s easy to assume a man my age wouldn’t be able to relate to Margaret or Barbara’s journeys of self-discovery. While I admittedly saw much of myself in what I described to McAdams as her on-screen husband’s, played by Benny Safdie, “quintessential dumb dad face” at multiple points, every character resonated. McAdams adds: “Benny was so good at playing just ‘good dad’ and just trying to keep up with the girls.”

Despite being a star who’s dazzled audiences in Hollywood for over two decades, McAdams, 45, doesn’t do many media interviews. With memorable turns as a woman torn between two men in the romantic period drama “The Notebook” to her stunning portrayal of a closeted Orthodox Jewish woman in “Disobedience,” the Canadian-born actor’s versatility has been beloved by fans worldwide.

Paramount/courtesy Everett Collection

One of her most iconic roles was as high-schooler Regina George, the self-proclaimed Queen of the Plastics in the 2004 teen comedy “Mean Girls.” An adaptation of the Broadway musical version of the movie will be released in January by Paramount Pictures, with scribe Tina Fey returning. Unfortunately, it sounds like McAdams will not appear despite Fey and Tim Meadows reprising their roles, although it sounds like we came close to having a Regina cameo.

“Tina and I sort of dabbled with a few ideas, but it was tough to make it all work in the end,” she says. “I was really down for whatever she wanted to do. I think the direction it went in will be fantastic and I cannot wait to see it.”

And regarding the pink plastic elephant in the room — in early November, a Black Friday Walmart commercial aired that reunited original “Mean Girls” cast members Lindsay Lohan, Amanda Seyfried and Lacey Chabert, but without McAdams — we finally got an answer why.

McAdams shares: “I don’t know; I guess I wasn’t that excited about doing a commercial if I’m being totally honest. A movie sounded awesome, but I’ve never done commercials, and it just didn’t feel like my bag. Also…I didn’t know that everyone was doing it. I would, of course, always love to be part of a ‘Mean Girls’ reunion and hang with my plastics, but yeah, I found that out later.”

So, does that mean “Mean Girls 2” is still possible? That would be so fetch.