Entertainment Movies Musical Movies Meryl Streep Says 'Mean Girls' and 'Romy and Michele' Are 'Pretty Much Religious Texts in My House' Amanda Seyfried recalled how Meryl Streep first introduced herself on the set of "Mamma Mia!" as a big fan of "Mean Girls" By Jen Juneau Jen Juneau Jen Juneau is a News and Movies Staff Writer at PEOPLE. She started at the brand in 2016 and has more than 15 years' professional writing experience. People Editorial Guidelines Updated on September 13, 2023 01:43PM EDT From L: Amanda Seyfried in Mean Girls (2004); Meryl Streep on April 24, 2023, in New York City; Lisa Kudrow in Romy and Michele's High School Reunion (1997). Photo: CBS via Getty Images; Dimitrios Kambouris/Getty Images; THA/Shutterstock Meryl Streep isn't, like, a regular mom, she's a cool mom — both on and offscreen! In an oral-history interview with Vogue (conducted prior to the ongoing actors' strike) alongside much of the Mamma Mia! cast and crew to celebrate the musical film's 15th anniversary, the three-time Oscar winner was lauded by costar Amanda Seyfried for the way she introduced herself to Seyfried, 37, on set. "I went to [costume designer] Ann Roth’s studio for my first fitting and Meryl was there when I showed up. The first thing she said was, 'You’re very big in my household because of Mean Girls!' " recalled Seyfried, who starred as Karen Smith in the now-classic 2004 teen comedy. "I’m sure she can imagine how intimidating it would be for someone like me to play her daughter, and I believe she said that with every intention of making me feel more comfortable," Seyfried added of Streep, 74. "She took herself off the pedestal that I created for her in one sentence, and it meant the world to me." But it was a natural introduction for Streep, as she and her family — which includes daughters Mamie Gummer, 40, Grace Gummer, 37, and Louisa Jacobson, 32 — are big fans of the Tina Fey-written movie, which also starred Lindsay Lohan, Rachel McAdams and Lacey Chabert. Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human-interest stories. From L: Lindsay Lohan, Amanda Seyfried, Lacey Chabert and Rachel McAdams in Mean Girls (2004). CBS via Getty Images 'Mean Girls' Musical Movie: Everything to Know "Mean Girls and Romy and Michele’s High School Reunion are pretty much religious texts in my house," Streep told Vogue, shouting out the 1997 best-friends comedy starring Mira Sorvino and Lisa Kudrow. "Those are the movies that I rewatch with my girls the most to this day." "So I was very familiar with little Amanda going into Mamma Mia!" added Streep. "She became like another daughter to me." A smash hit based on the musical of the same name, Mamma Mia! was followed by a sequel, Mamma Mia! Here We Go Again, in 2018. In a May interview with Deadline, Mamma Mia! franchise creator and producer Judy Craymer said a third movie musical was in its "earliest stages." She also shared that she had come up with a way to bring Streep back. "I don't want to over-egg it, but I know there's a trilogy there," Craymer, 65, said at the time of the unofficial news. "There is a story there, and I do think Meryl should come back, and if the script is right, she would, I think, because she really loved playing Donna." Meryl Streep and Amanda Seyfried in Mamma Mia! (2008). Universal Pictures/Relativity Media/Littlestar/Playtone/Kobal/Shutterstock 'Mamma Mia!' Director Ol Parker Teases Possibility of Third Franchise Film: 'Wouldn't It Be Lovely?' While there's still no official word on a third installment, Craymer told Vogue in the new interview that there "has to be another one because people want it," but "the trouble is we’re all getting older." "But," she added, "we couldn’t be in a better place as far as having a cast who are eager to do it." Though her character Donna was killed off in the 2018 sequel, Streep said, "if there’s an idea that excites me, I’m totally there." "I’m up for anything," she added about a sequel. "... I told Judy if she could figure out a way to reincarnate Donna, I’m into that. Or it could be like in one of those soap operas where Donna comes back and reveals it was really her twin sister that died." Streep joked, "We may have to call it Grand-Mamma Mia! by the time we make it!"