Thank you for the photos that were requested.
I would start giving her 1 Calcium Citrate+D3 tablet once daily for 3-5 days. Pull down on her wattles, pop the Calcium tablet right into the beak and let her swallow.
Be sure that her crop is emptying.
Giving an antibiotic may be helpful. Baytril is one of the strongest and you'd want to throw out eggs for at least 14days after last dosage. If you unable to find Baytril, then Amoxicillin would work. Same withdrawal period.
She may be having some reproductive problems, hard to know. Stress can affect them, but likely this has been going on for a little while.
See that her crop is emptying and if possible, get a fecal float to see if worms are part of the problem too. If not, then deworming is a good idea.
Safeguard (Fenbendazole) or Valbazen (Albendazole) can be used to deworm your hen. You can order both online or you may be able to find them in certain feed stores.
To treat most worms that poultry can have except for Tapeworm you can use Safeguard (Fenbendazole) or Valbazen (Albendazole). Both are given orally by weight; they do not mix well with water.
Safeguard dose is 0.23ml per pound of weight given orally once a day for 5 days in a row.
---OR---
Valbazen dose is 0.08ml per pound of weight given orally once, then repeated in 10 days
Here's how to give oral medications:
https://www.backyardchickens.com/ar...dications-to-all-poultry-and-waterfowl.73335/