Sadie Sink did briefly appear in the recent trailer for Spider-Man: Brand New Day, but Marvel and Sony are clearly doing their best to preserve the identity of the Stranger Things alum's character for as long as possible.
Possible spoilers follow.
There are other possibilities, of course, but given the persistent rumours and everything that has been disclosed about Sink's character, we'd be very surprised if she didn't turn out to be Jean Grey, and it sounds like the studio has some major plans for the powerful mutant.
According to MTTSH, Sink has "signed a deal for 5 movies with Marvel, including an option for TV shows."
Brand New Day is one, the X-Men reboot makes two, and we have also heard that Sink will appear in Avengers: Secret Wars. Marvel Studios is expected to follow the Multiverse Saga with the Mutant Saga, and is believed to have plans for at least one X-Men-centric Disney+ series. With this in mind, Sink's deal really isn't too surprising.
Another recent rumor claimed that Brand New Day will feature "more than one mutant," which could suggest that Marvel has been quietly casting the new team.
MTTSH has also shared a couple of Avengers: Doomsday rumors, but they were previously covered in the recent plot leak.
Following the record-breaking success of Spider-Man: No Way Home, Spider-Man: Brand New Day begins a brand new chapter for Peter Parker and Spider-Man. Four years have passed since the events of No Way Home, and Peter is now an adult and living alone after erasing himself and the memories of him from those he loves. In a New York that no longer knows his name, he has devoted himself wholeheartedly to protecting his city as Spider-Man full-time.
But as the demands on him grow, he is put under increasing pressure. This triggers an unexpected physical change that threatens his existence, while a strange wave of crime emerges - and gives rise to one of the most dangerous threats he has ever faced.
Spider-Man: Brand New Day is directed by Destin Daniel Cretton and written by Chris McKenna & Erik Sommers. The film is produced by Kevin Feige, Amy Pascal, Avi Arad and Rachel O'Connor. The cast includes Tom Holland, Zendaya, Sadie, Jacob Batalon, Jon Bernthal, Tramell Tillman, Michael Mando and Mark Ruffalo.
Spider-Man: Brand New Day is set to hit theaters on July 31, 2026.