I noticed a few days ago she was moving her neck weird...I guess jerky and side to side?
She is also very skinny. She lost alot of weight during her last crop problem
her crop feels squishy again
She has lost alot of feathers on her head, and when I looked closer at her it's as if they broke off and the quill is still there.
9 months old
Well now her crop isn't as full and hanging as much as the first time, but it is fuller than it should be and squishy, or doughy. I think maybe it's just a slow crop, proably pendulous
She's on her second day of corid. She's been doing her neck winding more
What type of food/treats do you feed?
Does she have grit available?
Can you post photos of her or a video of her actions?
When was the last time she laid an egg?
Do you have a rooster?
What's the purpose of the Corid? Do you suspect Coccidiosis - can you take a fresh poop sample to your vet for a fecal float?
Since she is having crop problems, the neck movement could be due to adjusting the crop. Vitamin E deficiency also some to mind.
If the crop bra worked for her, you may want to put that back on. Provide her with plenty of water, poultry grit free choice and give only her normal feed along with a little chopped egg and yogurt as a treat (no scratch or hard to process foods). See if you can get the crop moving it's contents.
http://www.backyardchickens.com/a/impacted-slow-and-sour-crops-prevention-and-treatments
Adding some poultry vitamins that contain Vitamin E and B1 is also a good idea, the chopped egg will supply enough Selenium for Vit. E uptake.
The broken feathers on the head sounds like she has been picked on, or if you have a rooster/cockerel it could be from mating.