It may not be wry neck if she has control enough to target and pick up a bite of food. Wry neck is neurological and it interferes with the chicken's ability to control their body's movements.
There may be something else going on. I suggest you isolate her in a section of the run if you can. Many of us have a "jail" section for such a purpose, but you can erect a temporary barricade in a corner of the run where she can stay for a few hours without the interference of the others.
Clean it of all poop so you can then observe her poop so we can assess if she has a health issue. Give her regular food and water and then observe her behavior. Watch to see how active she is, if she plants herself in a corner or faces a wall and is fluffed up. Watch her eyes for droopiness, and also watch how she holds her tail. Watch to see how her appetite is.
Meanwhile, try to think what she was doing prior to this, where she was scratching around and what she was eating. Think about anything toxic that she may have encountered, from insecticide to petroleum distillates to toxic plants.