If she were my duck I would give her a though exam, which would include checking the inside of her vent for a stuck egg. I would also check her fett and legs very closely for any swelling, heat and verify that the range of motion (flexibility) in all legs joints was normal. If I couldn't find anything I'd put her in a dog crate with a high protein turkey or gamebird starter. She would also be put in a bathtub of shallow warm water once a day.
-Kathy
-Kathy