I think my bantam is dying! Anyone know what could be wrong?

Yesterday my little bantam chicken was doing good. She had recently been separated from the rest of the flock, due to them incessantly picking on her. Today she will not move, she slumps over when it touch her, her breathing seems labored, she won't open her eye's, or move at all, and she's cold. I think she's dying!! Does anyone know what could be wrong?? Like I said she was fine yesterday, and other than a few minor injuries from the other chickens pecking her (missing feathers, and a minor eye problem). She was walking around, talking, eating, and drinking yesterday. I'm just puzzled as to what could make her go down hill so fast. I don't see anything else wrong with her! Anyone know what could be happening??