Y/N is the baby sister to Tony Stark and she's just as smart as him but she's also very, very different from him. Thats why she joins Steve to help prove that Bucky Barnes is innocent. When things go South, she joins Steve and Bucky in Wakanda where she stays to avoid being found and arrested. Bucky and Y/N soon grow closer and fall in love. But that love is short lived when the fate of the entire world is at stake.