Darcy Lewis first appeared in the movie Thor, where she was played by the actress Kat Dennings. Dennings reprised her role over multiple Marvel Cinematic Universe projects. Darcy finally made the leap to comics in Scarlet Witch #1.
Darcy Lewis worked together with colleagues Jane Foster and Erik Selvig in New Mexico and was one of the first mortals to meet the Asgardian God, Thor. She was instantly attracted to Thor, but nonetheless remained her casual self and helped him and Jane and Erik to defeat Thor's evil half-brother Loki.
Thor: The Dark World (2013)
Darcy was seen again some months after the big fight with Loki. She still worked with both Jane and Erik, and discovered the teleportational holes in London, England that led to the defeat of Thor's newest advisory, Malakith the Accursed.
Darcy appears in the fourth episode of Disney+ online series WandaVision. She is called by a joint task force between S.W.O.R.D. and the FBI to uncover the mysterious presence of Westview, New Jersey and the disappearance of S.W.OR.D. Agent Monica Rambeau. Darcy and FBI agent Jimmy Woo discover the inhabitants of Westview include Scarlet Witch and Vision of the Avengers and several missing individuals are in kept in some sort of contained facility/pocket dimension centered around retro television shows from different time periods.