Ever since Stranger Things ascended to the pinnacle of television's most captivating hits in recent years, the series has propelled its cast members into international limelight. This has opened doors for many of the show's stars to venture into other projects, with Millie Bobby Brown starring in the Enola Holmes movies as a prime example. Now, Sadie Sink seems poised to make a splash as one of the most notable former child stars from Stranger Things, as she prepares to join the Marvel Cinematic Universe.
Photos of Sink on the set of the upcoming MCU movie Spider-Man: Brand New Day went viral, sparking a myriad of speculations about her role in the film. After weeks of rumors swirling, Sink finally broke her silence on her future in the MCU.
In October 2025, photos of Sink on the set of Spider-Man: Brand New Day surfaced on social media. Roughly a month later, in November 2025, Sink was interviewed by Entertainment Weekly while promoting the final season of Stranger Things on Netflix. When asked about Spider-Man: Brand New Day, she joked about the dark and puffy jacket she was photographed wearing on the set of the MCU movie. "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'll be the situation for a bit, it seems."
Beyond joking about her wardrobe, Sink revealed a fascinating fact about her joining the MCU. While some fans may have expected Marvel Studios to have been circling Sink for a long time before she was cast, she revealed that negotiations for her MCU debut began "not as far back as you would think." Instead, Entertainment Weekly's article stated that Sink began conversations with Marvel while filming Stranger Things 5.
As the set photos of Sink in the MCU went viral, there was a lot of discussion and articles about theories about who Sink could be portraying in the film. Since she wasn't photographed wearing a superhero or supervillain suit that would have instantly revealed her role, there were plenty of different rumors circulating. One of the most common theories was that Sink would portray Rachel Cole-Alves, a character linked to the iconic Marvel antihero The Punisher, while others thought she could be cast as Jean Grey.
During the aforementioned Entertainment Weekly interview, Sink was asked about the rumors that she could be portraying the iconic X-Men hero, Jean Grey. Unsurprisingly, the Stranger Things star didn't confirm or deny that she had been cast as the beloved mutant character. Instead, Sink responded by pointing out that there had already been rumors about her portraying Jean Grey before she was photographed on the Spider-Man: Brand New Day set. "That was happening before I even knew that I would be working on this project. I was like, 'Wait! What are people talking about?'"
Given that Jean Grey typically sports red hair in both comic book and film adaptations of the character, many young female actors with fiery hair get linked to the character. Sink's final comment to Entertainment Weekly about her upcoming MCU role was to point out that this phenomenon is somewhat silly because hair dye and wigs exist. "A lot of people forget that hair color can change, but, yeah, I understand all of the theories."
