A recent post on X has sent Spider-Man fans into a frenzy, claiming that Sadie Sink will portray Mayday Parker, the daughter of Peter Parker and MJ, in the upcoming MCU film Spider-Man: Brand New Day, set to release on July 31, 2026. While this news has not been officially confirmed by Marvel Studios or Sony, the rumor has sparked intense speculation about the direction of Tom Holland’s fourth solo outing as Spider-Man and what it could mean for the franchise’s future. Let’s dive into the details of this rumor and explore its potential implications for the MCU’s wall-crawler.
The rumor originates from a post by @MCUSource on X, shared on April 1, 2025, which boldly stated, “Sadie Sink will play Peter and MJ’s daughter Mayday Parker in #SpiderManBrandNewDay!”. In the comics, Mayday Parker, also known as Spider-Girl, is the daughter of Peter Parker and Mary Jane Watson, introduced in the alternate future timeline of the MC2 universe. Mayday inherits her father’s spider-powers and takes up the mantle of Spider-Girl, becoming a hero in her own right. The idea of Sadie Sink, known for her role as Max Mayfield in Stranger Things, playing such a significant character in the MCU has ignited excitement, but also raised questions about how this could fit into the current timeline of the MCU’s Spider-Man narrative.
Spider-Man: Brand New Day picks up after the events of Spider-Man: No Way Home (2021), where Peter Parker (Tom Holland) made the heart-wrenching decision to have Doctor Strange (Benedict Cumberbatch) cast a spell erasing the world’s memory of his identity to protect the multiverse. This left Peter isolated, with MJ (Zendaya) and Ned (Jacob Batalon) no longer remembering him. The film’s title, inspired by the 2008 Marvel Comics storyline Brand New Day, suggests a fresh start for Peter as he navigates life as a more grounded, neighborhood Spider-Man. However, introducing Mayday Parker—a character from a future timeline—would require significant narrative leaps, such as time jumps, multiversal elements, or a drastic reinterpretation of the character.
Sadie Sink’s casting in Spider-Man: Brand New Day was confirmed earlier this year, though her role has remained a closely guarded secret, fueling a wide range of fan theories. At 22 years old, Sink is within the right age range to play a teenage Mayday Parker, potentially as a daughter from an alternate universe or a future timeline brought into the present through multiversal events tied to Avengers: Doomsday, which is set to release just two months before Brand New Day in 2026. The Brand New Day comic arc famously followed the controversial One More Day storyline, where Peter and MJ’s marriage was erased by the demon Mephisto—a plot point some speculate could be adapted in the MCU with a twist, possibly involving Mephisto claiming their future daughter instead.
However, the rumor of Sink as Mayday Parker raises some logistical challenges. Peter and MJ are not currently together in the MCU, and MJ doesn’t even remember Peter. For Mayday to exist, the story would need to either fast-forward significantly, showing Peter and MJ reuniting and starting a family, or introduce Mayday through multiversal means, perhaps as a variant from another reality. Some fans on X have embraced this idea, seeing it as a bold way to expand Spider-Man’s legacy, while others question its feasibility given the current state of Peter’s life. Additionally, earlier speculation suggested Sink might play a villain like Menace, a new love interest like Carlie Cooper, or even an X-Men character like Jean Grey, indicating the uncertainty surrounding her role.
The potential inclusion of Mayday Parker could also tie into broader MCU plans. With Avengers: Secret Wars (2027) expected to reshape the multiverse and introduce the X-Men, Mayday’s introduction might serve as a stepping stone to a new generation of heroes. Director Destin Daniel Cretton (Shang-Chi and the Legend of the Ten Rings) has teased that Brand New Day will explore a “fresh start” for Peter, which could involve mentoring a younger hero like Mayday, mirroring Peter’s own journey under Tony Stark’s guidance [Ref web: 15, Ref web: 16]. This would also align with fan theories about Peter maturing as a hero, potentially setting the stage for him to pass the mantle to a successor.
While the rumor is exciting, it’s worth noting that X posts are often speculative and not always reliable. Marvel Studios has a history of keeping major casting and plot details under wraps, and Sink herself has remained coy about the rumors, saying on the Happy Sad Confused podcast, “I have nothing to say about this. The rumours are cool, though. It’s an awesome rumour… I know the character. It’s a great character”. Without official confirmation, fans should approach this news with cautious optimism.
If true, Sadie Sink as Mayday Parker could mark a transformative moment for the MCU’s Spider-Man franchise, introducing a new dynamic to Peter’s story and setting up a legacy for the future. Whether through multiversal magic or a bold time jump, the idea of Peter facing the challenges of fatherhood—or confronting a daughter he never knew—adds emotional stakes that could resonate deeply with audiences. For now, fans will have to wait for more concrete details as Spider-Man: Brand New Day begins shooting this summer, but one thing is certain: the web-slinger’s next chapter promises to be unlike anything we’ve seen before.
