Sadie Sink joined the cast of Spider-Man: Brand New Day in March 2025, but her role remains a well-guarded secret. The actress continues to offer cryptic responses eight months later. At the Stranger Things Season 5 premiere in November, Entertainment Tonight asked her for one word to describe her character. She replied, “I thought this was the Stranger Things premiere. I wasn’t prepared.” When pressed further, she simply said, “Mmm, no.”
This evasiveness has ignited fan speculation, with social media theories running wild about her mysterious Marvel Cinematic Universe debut. Here’s what the fans have to say on X,
Rachel Cole, apparently pic.twitter.com/U87xEU6seg
She’s playing Jean Grey pic.twitter.com/C0PyWqvZjr
This already feels like a villain origin story
Everything Confirmed About Sadie Sink’s Spider-Man: Brand New Day Role
Sony Pictures and Marvel officially announced Sink’s casting in March 2025 for the film (via Deadline), directed by Destin Daniel Cretton. She joins Tom Holland as Peter Parker, Zendaya as MJ, and Jon Bernthal as Frank Castle. Mark Ruffalo and Michael Mando will also appear as Bruce Banner and Mac Gargan. Principal photography started in mid-2025 in London, with the film scheduled for release on July 31, 2026.
Set images that surfaced in October provided the first visual clues about Sink’s character. The photos show her in camouflage pants and military boots (via IGN), with footage depicting her on a stretcher being transported to the Department of Damage Control (via ComicBookMovie).
This suggests her character might possess superhuman abilities. Sink was also spotted in different clothing, including a beige hoodie and a khaki coat, which points to multiple costume changes throughout the film.
An insider claimed she is a villainous shapeshifter, while another reported her character is an ally to Peter Parker. When asked about the Jean Grey rumors in March, Sink said in a Happy Sad Confused podcast,
No, I have nothing to say about this. The rumors are really cool, though.
These visuals have fueled intense fan debate over her identity. The leading theory suggests she is Jean Grey, aligning with Marvel’s plans to introduce the X-Men and matching Sink’s red hair. Others believe she is Rachel Cole-Alves, a former Marine who partners with the Punisher and wears a similar outfit. Additional speculation points to Firestar or Mayday Parker.
Sadie Sink Reveals Taking Special Objects From Stranger Things Set
Sink shared details about mementos from the Stranger Things set. On November 7, 2025, at LAX, she revealed to TMZ that she kept Max Mayfield’s iconic skateboard after playing the character for nearly a decade. The actress said the skateboard now hangs above a doorway in her home as a personal keepsake from her time on the show.
Sink also took the cassette Walkman that saved Max’s life in Season 4. The device played Kate Bush’s “Running Up That Hill,” allowing her character to escape Vecna’s curse. The final season of Stranger Things will be released in three parts, with the first debuting on November 26, 2025, the second on December 25, 2025, and the finale on December 31, 2025.
Sadie Sink’s role in Spider-Man: Brand New Day remains unconfirmed as production continues. Fans are left to analyze every detail for hints about her character’s identity. The mystery will likely persist until closer to the film’s release, leaving audiences to speculate about one of the MCU’s most anticipated new additions.
What role do you think Sadie Sink is playing in Spider-Man: Brand New Day? Share your theories in the comments below.
Spider-Man: Brand New Day is currently scheduled to be released on July 31, 2026.
