I would do the massages as directed in the article for treatment of impacted crop. Hopefully it'll help!
Also, I wouldn't hold off on feed, she needs it. So try getting some fish, meat, eggs, or moistened feed into her. :)
Do you mind getting a picture of her just so I can see how she's looking?
Have you checked her crop early in the morning to make sure it's empty? If not, make sure to do that.
Here's an article on crop issues.->
https://www.backyardchickens.com/articles/how-to-treat-sour-crop-and-impacted-crop-and-how-to-know-which-one-youre-dealing-with.73607/
How full is her crop?