Darcy and Nick Fury knew each other long before the events of Thor. Nick dated her mother an he was Darcy’s favorite boyfriend of her mothers, her mother screws it up by getting back together with her ex-fiancé. Darcy and Nick stayed in contact though and helped her pay for college and she knew what he actually did. She was in pol-sci so she could join SHIELD and be his left hand. In the end she became the Avengers liaison.