I'm still unsure if I've dreamt this up but I'm searching for a fic where Darcy is manipulated by Ian Boothby into sleeping with Steve Rogers, then she gets kidnapped and escapes later on. Sharon Carter appears in the fic and helps her out and Steve and Bucky are part of the rescue team I think. Bucky mentioned that he used to train hop. She also finds out she's pregnant and has developed some reflexes and invulnerability from the fetus. Yeah, so if anybody can prove this story is exists.