Sadie Sink Rumoured for Rachel Summers Role in Spider-Man 4

Marvel Studios’ recent casting announcement has left audiences rather perplexed, as Sadie Sink, best known for her work in Stranger Things, is set to appear in the next Spider-Man instalment. She will join Tom Holland in Spider-Man: Brand New Day, and speculation about her character has been rife. Some have suggested she could portray the daughter of Tobey Maguire’s Spider-Man and Mary Jane, while others have floated the idea of her taking on the role of Jean Grey, the formidable mutant.

However, the latest whispers point towards Sink embodying Rachel Summers, the time-travelling offspring of Scott Summers and Jean Grey. This theory, which has gained traction online, seems to fit neatly with Marvel’s current direction.

Fan Theories and the Multiverse

One particularly popular theory, originating from a Reddit post, proposes that Jean Grey (the Phoenix) and Scott Summers (Cyclops) have sent Rachel into a different timeline—the so-called sacred timeline—in an effort to shield her from a looming threat. The post also speculates that Dr Doom, rumoured to be the next major antagonist in the Marvel Cinematic Universe, is targeting children with extraordinary abilities. This idea aligns with Marvel’s recent trend of introducing younger heroes, such as Ms Marvel and America Chavez, and even Thor’s daughter has joined the fray.

According to these fan musings, Dr Victor von Doom may have already crossed paths with the X-Men, prompting the two mutants to send their daughter to Earth-616 for her own safety.

Gender Swaps and Character Reimaginings

Marvel has not shied away from reimagining its characters, as seen with the gender-swapped Silver Surfer in The Fantastic Four: First Steps. This has led some to wonder if Rachel Summers’ introduction is another example of the studio’s willingness to experiment with established roles.

It’s worth noting, however, that the Silver Surfer in the recent film was not Norrin Radd but Shalla-Bal, a character who already exists in the comics as the original Surfer’s love interest. As for Rachel Summers, she is not simply a female version of Cable; rather, she is his sister, possessing her own unique set of powers, including time-travelling abilities. Josh Brolin previously portrayed Cable in Deadpool 2, but Cable is actually the son of Cyclops and Madelyne Pryor, Jean Grey’s clone, not Jean herself. Madelyne Pryor has already made an appearance in X-MEN ‘97.

There is also the possibility that mutants are already present in Earth-616, with Rachel serving as the first to make contact. Some fans believe that, with the world having forgotten Peter Parker’s identity, the X-Men might approach him, offering support now that he is isolated. After all, Xavier’s School is known for welcoming gifted youngsters.

Rachel Summers: Powers and Place in the Marvel Universe

Rachel Summers is the daughter of Cyclops and Phoenix, and half-sister to Nathan Summers, also known as Cable. The siblings have even fought side by side in teams like X-Force.

While not a conventional time traveller, Rachel combines telekinesis with the Phoenix Force, enabling her to move through both time and dimensions. Uniquely, she is the only version of herself across the multiverse, with no alternate counterparts in any reality.

Marvel enthusiasts are keen to see how these theories play out, especially with Avengers: Doomsday scheduled for release on 18 December 2026.