Sadie Sink gave a major hint to her Spider-Man: Brand New Day character by subtly shutting down a major theory in a recent interview. Aside from the mysterious plot of Spider-Man's next solo MCU movie, speculation has been rampant about Sink's unknown Marvel character, leading to plenty of theories. In October 2025, the first glimpse of Sadie Sink's mystery MCU character was spotted on set, with the actress sporting red hair and wearing camouflage pants and boots.
As expected, Marvel diehards instantly speculated that she could end up playing characters like Jean Grey, Mayday Parker, or Firestar (aka Angelica Jones) due to her red hair. However, one comment from Sink in a recent interview essentially debunked these major theories.
Speaking with Entertainment Weekly ahead of Stranger Things Season 5, Sadie Sink provided a hint about her MCU character, pointing out that "hair color can change," hinting that her Marvel hero (or villain) will not have red hair in Brand New Day:
"A lot of people forget that hair color can change, but, yeah, I understand all of the theories."
Sink's comments seemingly debunk a major theory about her Marvel character being a redhead. If true, then Sink essentially shuts down the speculation that she could be playing the likes of Jean Grey and Mayday Parker.
Interestingly, entertainment insider Daniel Richtman shared a post on X of an image of Sadie Sink sporting blonde hair, indicating that her character will have a similar hair color in Brand New Day.
In the same interview, Sink reflected on trying to preserve the secrecy for her MCU character:
"Tom [Holland] 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."
Sink also confirmed to Entertainment Weekly that conversations about joining the Marvel Cinematic Universe happened while she was filming Stranger Things Season 5, noting that it's "not as far back as you would think."
The rising star also directly addressed the theory that she is playing Jean Grey in her upcoming MCU debut, clarifying that she was unaware that fans were already speculating that she is playing the X-Men hero:
"That was happening before I even knew that I would be working on this project, I was like, ‘Wait! What are people talking about?’"
Sadie Sink recently showed off her ripped abs for Spider-Man 4 during the world premiere of Stranger Things Season 5 in Los Angeles, strongly indicating that she is in superhero shape or at least part of the action when Spider-Man throws down with the likes of the Hulk and Punisher in Brand New Day.
However, this latest comment from the actress about debunking the redhead theory means that some fans will have to go back to square one in piecing together who her Marvel character really is.
Directed by Destin Daniel Cretton, Spider-Man: Brand New Day continues the story of Tom Holland's Peter Parker following the game-changing ending of No Way Home, where his identity was erased due to Doctor Strange's spell. Spider-Man: Brand New Day premieres in theaters on July 31, 2026.
Sadie Sink's Latest MCU Comments Should Drum Up Hype for Spider-Man 4
Based on Sadie Sink's comments and Daniel Richtman's hints that her character in Spider-Man: Brand New Day is blonde, the speculation train about her mystery hero (or villain) will be off the charts once more, essentially drumming up hype for the already stacked MCU sequel.
At this stage, it's reasonable to assume that Sink could end up playing a version of Gwen Stacy, considering that this character is the most prominent blonde female protagonist in Spider-Man lore. This would be an obvious revelation, but given the mystery surrounding the character, there has to be a deeper meaning behind the actress' role.
In September 2025, a rumor circulated that Sadie Sink would be playing a shapeshifting villain in Brand New Day. This led to a theory stating that Sink could be playing a Marvel foe named Shathra. In fact, Sink's latest comments about the fact that "hair color can change" could allude to this theory about her shapeshifting villain.
Despite that, another report claimed that Sink is part of the stacked cast of Avengers: Secret Wars, meaning that her character is a big deal in the grand scheme of things in the Multiverse. That said, it's possible that Sink's latest comment could be a red herring, and she could end up playing a disguised Jean Grey or Mayday Parker with different hair to throw off some fan theories and not spoil the surprise reveal in Brand New Day and Secret Wars.
