Sharon Carter, alias Agent 13, is a supporting character from 2014 film Captain America: The Winter Soldier and 2016 film Captain America: Civil War. Sharon Carter was a field agent with S.H.I.E.L.D. who was given a mission to discreetly monitor and protect Steven Rogers at his home when he was off duty. She adopted a cover as a nurse and moved into an adjacent apartment to further her assignment. Carter got through the ordeal of S.H.I.E.L.D.'s subsequent collapse, and turned instead to the Central Intelligence Agency where she could continue to use her skills to best effect.