The female lead in The Winter Soldier story arc is Sharon Carter aka Agent 13, Peggy's niece. Anna Kendrick, Felicity Jones and Imogen Poots are at the top of a very short list of actresses to portray the role.
In the comics, Bucky/Winter Soldier kidnaps Sharon. Cap is able to deduce with the help of Nick Fury that the villain is his former friend. No word on if or how much of Nick Fury will feature in the film, though he's a huge supporting player in the comic.
That been said, who knows what directors Joe and Anthony Russo (and Marvel) are planning, considering the overall story arc has to tie Cap's involvement in Joss Whedon's The Avengers 2.
Captain America: The Winter Solider hits theaters April 4, 2014. Do you like any of these actresses for the role or perhaps someone else?