I would give her 1-2 tsp of chilled coconut oil cut into small pieces to peck, or some mineral or olive oil in a small spoonful of scrambled egg. Offer her water with electrolytes continuously and hold off on any food today. Massage her crop several times a day to break up the impaction. Check her crop first thing in the morning before she eats or drinks. If it is still full and firm, repeat what you did today. Do you have granite poultry grit available for them to take as they need it? Have you wormed them recently? What do you normally feed? Here is a good article to read on crops:
https://www.backyardchickens.com/ar...w-to-know-which-one-youre-dealing-with.73607/
https://www.backyardchickens.com/ar...w-to-know-which-one-youre-dealing-with.73607/