As "Spider-Man: Brand New Day" gears up for a July 31, 2026, release, star Sadie Sink's role in the film remains a closely guarded secret by Marvel Studios. However, her MCU trajectory appears to extend far beyond this Spider-Man sequel. According to Deadline senior reporter Baz Bamigboye, Sadie Sink is confirmed to join "Avengers: Secret Wars," positioning her as a pivotal new face in the Multiverse's ultimate showdown.
The report clarified that while there was initial speculation she would join "Avengers: Doomsday," that film has already completed principal photography, making her involvement more likely for the 2027 finale, "Secret Wars." However, "Doomsday" is slated for reshoots next year, so Sink's appearance in both films remains a possibility.
Deadline's Bamigboye wrote in his report, "I don't know who she's playing in 'Spider-Man: Brand New Day,' but what I do know is that she's joining the next 'Avengers' movie, which is shooting in London," offering a glimpse into the "Stranger Things" star's future in the MCU.
Sadie Sink's character identity currently remains one of the biggest mysteries in the MCU. Earlier rumors suggested she might portray the comic villain Shathra or the Punisher's red-headed partner, Rachel Cole-Alves, but these speculations are gradually being dismissed given the interconnected nature of "Secret Wars."
Consequently, many fans now lean towards the belief that Sink will play a Multiversal version of Mayday Parker, the daughter of Peter Parker and Mary Jane Watson.
If these rumors hold true, she could be the daughter of Tobey Maguire's Spider-Man, arriving on Earth-616 to warn or assist Tom Holland's iteration of the web-slinger.
Another theory suggests that Mayday's universe might have been destroyed by an "Incursion" event, making her a crucial messenger seeking aid across the Multiverse. Recent reports also indicate that Tobey Maguire is actively preparing to return for "Avengers: Doomsday," further highlighting a potential storyline centered on finding his lost daughter.
Furthermore, early whispers also placed Sadie Sink on a shortlist for the MCU's Jean Grey, adding another layer of intrigue to her eventual role.
Mayday Parker first appeared in "What If...?" #105 in February 1998, as the child of Peter and MJ from an alternate timeline. In that reality, Spider-Man retired after losing a leg in a fierce battle with the Green Goblin, shifting his focus to family life.
Currently, the MCU's two culminating films, "Avengers: Doomsday" and "Avengers: Secret Wars," are slated for release on December 18, 2026, and December 17, 2027, respectively.
via： Deadline