[1][2] Schaeffer grew up in Agoura Hills, California, and was inspired by filmmakers Quentin Tarantino, Robert Rodriguez, Allison Anders, and Lisa Cholodenko as a teenager.

in English in 2000 after completing an 81-page senior thesis, titled "Splinter in the Mind: The Dilemma of the Political Dystopian Protagonist and the Cyberpunk Hero", under the supervision of Maria DiBattista.

[3] She wrote, produced and directed her first feature film, a science fiction romantic comedy called TiMER starring Emma Caulfield.

[2] Schaeffer wrote The Hustle, a Dirty Rotten Scoundrels remake starring Anne Hathaway and Rebel Wilson,[9] which was released in May 2019.

[15] She was also hired by Marvel to write the first and final episodes and serve as head writer for the Disney+ miniseries WandaVision, in January 2019.