She also happens to be a prisoner whom you rescue while you are on a mission, and there is also the option to play just about every mission as her. You can make her as your protagonist, where she will also be seen in many cutscenes. After all, she runs Mother Base, and she will also command the game’s soldiers.
Just how does one unlock this femme fatale? You will need to go to Prisoner Extraction 02 in Side Ops, where it tends to come up with extremely rare woman prisoners. From there, when picking a mission in which you would like to get involved in, head to Character and then you can continue the game as her. You can see her combat stats rise the more you play, which will affect your health pool mainly, although there is not much other significant differences between her and Snake. Pretty cool, huh?