Spider-Man: Brand New Day introduces Sara Grey, Jean Grey’s little-known sister, and significantly alters her comic-book history by depicting her as a psychic with a direct role in shaping Jean’s powers. The change matters because it expands the MCU’s mutant mythology and positions Sara as a potentially consequential character for future films.

In Marvel comics, Sara first appeared in 1980 as Jean’s non-mutant sister and was later absorbed by the Phalanx before being revived by Jean in a 2025 story. That revival gave Sara the ability to sense and unlock mutant powers, an idea previously suggested by X-Men writer Chris Claremont in the 1980s. The film instead presents her as a psychic, with flashbacks showing her teaching Jean to control minds before Damage Control abducts her.