I'm pretty sure it was post-Civil War), with Steve and Tony trying to work out their issues and living under the same roof. The rest of the world doesn't know Steve is alive for a while (with the exception of Carol and maybe a few other people). They're taking care of a girl who is a clone (sort of, because she's female unlike Steve), and she was trained as a weapon and didn't have a real name when they got her. The little girl ends up being called Maria and has a lot of emotional issues and what basically amounts to PTSD because she was raised to be a murder weapon. She has trouble making decisions and asserting her preferences and wants, especially at first.
That's all I can really remember. If you know what fic I'm talking about, please help because I'd love to finish reading it. Thanks!