The mystery surrounding who Sadie Sink is playing in Spider-Man: Brand New Day continues to grow.
In a sit-down with Entertainment Weekly to discuss Stranger Things season 5, the young actress said that she knows how to keep a secret.
“For the most part, I think people trust me to keep my mouth shut,” she observed when talking about the Netflix show. It’s a skill Brand New Day director Destin Daniel Cretton and the producers of the upcoming superhero film likely appreciate.
Every set photo from the production shows a concerted effort to keep her character under wraps — literally.
First look at Sadie Sink on set for Spider-man Brand New Day with Tom Holland
Via @UnBoxPHD pic.twitter.com/NtX6jQhKmG
— Spider-Man News (@SpiderMan_Newz) October 19, 2025
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Speaking of her co-star, Tom Holland, who is often seen in costume, Sink says, “Tom can wave at the fans because people know who he is, but then you get a glimpse of me and I’m like a penguin.”
That’s not a hint, of course, since The Penguin is a DC character…
But the list of potential Marvel characters Sink could be playing is long, and fans love to speculate.
Theories Abound
It’s unlikely that the red-headed Sink is playing Mary Jane Watson, Peter Parker’s iconic love interest. In this movie universe, Zendaya is already filling the role of MJ. Peter’s other comic book sweetheart, Betty Brant is also out, as Angouri Rice is playing a character with that name.
Finally, even though Sink notes, “A lot of people forget that hair color can change,” the blonde Gwen Stacy doesn’t appear to be it. If Sink is playing a non-costumed character, there would be no reason to hide her wardrobe.
(L-R): Cyclops (voiced by Ray Chase), Beast (voiced by George Buza), Jean Grey (voiced by Jennifer Hale), Roberto Da Costa (voiced by Gui Agustini), Jubilee (voiced by Holly Chou), Morph (voiced by JP Karliak), and Storm (voiced by Alison Sealy-Smith) in Marvel Animation’s X-MEN ’97. Photo courtesy of Marvel Animation. © 2024 MARVEL.
One popular theory is that Sink is playing Jean Grey, the telekinetic and telepathic mutant previously portrayed in the X-Men movies by Famke Janssen and Sophie Turner. It’s a bit of fancasting that started before Sink was signed to a Marvel movie.
“That was happening before I even knew that I would be working on this project,” she said. “I was like, ‘Wait! What are people talking about?’”
Sadie Sink on fans thinking that she will portray Jean Grey in the MCU:
“That was happening before I even knew that I would be working on this project. I was like, ‘Wait! What are people talking about?’”
(via: @EW) pic.twitter.com/aW7YjQAEr9
— The Marvelous Geek (@marvelousgeek__) November 25, 2025
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That’s not a no, and sometimes fans get their wish (Patrick Stewart did play Professor X, after all).
Sink is confirmed for Avengers: Secret Wars, which opens up even more possibilities for her role. Jon Bernthal’s Punisher will be in Brand New Day, but there’s no confirmation that he will appear in future movies.
Jon Bernthal as The Punisher – YouTube, Keep Cool Scenes
However, EW notes an idea that has started gaining traction is that Sink could be Rachel Cole-Alves, a Punisher sidekick. It’s another theory that Sink refuses to dismiss outright.
“People will just have to wait and see,” Sink said. “I’m excited for all of it to maybe be put to rest.”
Conclusion
For fans, the fun is in the waiting.
The conversation surrounding who Sadie Sink could be in Spider-Man Brand New Day is particularly refreshing when so many actors distract from their movies with political activism.
Sadie Sink at a photo shoot – YouTube, COVETEUR
Rather than stirring up controversy with stances on social issues or criticizing her audience, Sink is simply allowing fans to use their imaginations and wonder. There’s no drama casting dark shadows over the production, creating a bright spot in fandom that has been sorely missed by many.
Who do you think Sadie Sink is playing in Spider-Man: Brand New Day? Let us know in the comments!
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