History
Little is detailed about Squirrel Girl's life before the zombie plague arrived on Earth-2149, however it can be presumed that it followed much the same path as Squirrel Girl of Earth-616.
Squirrel Girl was one of the zombies about to eat Kitty Pryde's son, but she appeared and saved him. She offered herself to get eaten instead of her son, but the zombies agreed to eat them both. Unfortunately, for the zombies, Mephisto appeared and killed some of the zombies, however, she survived.[1]