Answer
Sharon Carter is the full name of Emily VanCamp's character in the MCU. She is first introduced in Captain America: The Winter Soldier as a S.H.I.E.L.D. agent and the niece of Peggy Carter. In the following film, Civil War, she is revealed to be a double agent working for Hydra. In Avengers: Endgame, she is shown to be working for the U.S. government as a liaison to the Avengers.