Here are some articles about crop treatments:
https://www.backyardchickens.com/articles/how-to-treat-sour-crop-and-impacted-crop-and-how-to-know-which-one-youre-dealing-with.73607/
https://www.backyardchickens.com/articles/impacted-slow-and-sour-crops-prevention-and-treatments.67194/
Sorry that you are dealing with this, but she seems young to be having this problem. Do you have granite grit available for her and the rest of the flock? I would be tempted to let her back out with her flock to free range. She might be more tempted to eat pine shavings if she is confined by...