If she has worms, you're going to need to treat for that now. You can treat with Corid at the same time, but her diagnosis was given by a vet. I'd treat for the problem at hand given by a medical professional, intestinal parasites. Separate her from the flock to observe her waste once treatment begins.
Most here will treat with Safeguard (Fenbendazole) at a dosage of .23lm per pound of weight given once per day for 5 days. If she is heavily infested, she will likely expel a large amount of worms shortly after the first dose, and it's critical that she remains hydrated throughout this process. If she doesn't like the Corid water, I'd remove it, and give fresh water only. Maybe she'll drink on her own...
Safeguard and water to hydrate are given the same way. See this link:
https://www.backyardchickens.com/ar...dications-to-all-poultry-and-waterfowl.73335/
You're going to want to assist her crop as much as possible for a day or two. Getting the crop moving is going to help get the medication and hydration into her. Water will also help to break the "clog", so give her some water; we use a medicine dropper and give about .5ml at a time. Wait about 5-10 minutes, then massage her crop for 5-10 minutes to soften the contents. If you feel that this is not working, you can freeze little pea-sized pieces of Coconut Oil and give them orally (3 or 4 of those pieces at once), wait 10 minutes for them to melt, then massage her crop again.
The crop issues, in my humble opinion, are possibly due to her gorging herself because the parasites are essentially starving her. Hydrate her, get her crop softened and moving a bit, then de-worm her. Keep an eye on her water intake throughout this process. No treatment will work if she doesn't stay hydrated. Manually water her via syringe/dropper if necessary.
Last, if one bird has intestinal parasites, it's likely they all need to be treated...