Using a syringe give her 1 tsp twice a day. When you give it to her orally, go slow because you don't want it to go into her lungs instead of down her throat.
Did you try giving her mineral oil? 1tsp twice a day. If there is an obstruction which in turn caused the sour crop, it should get the obstruction moving along. I also watered down the food to a mushy texture and added yogurt to it.
I went to feed my girls today and I noticed one of my hens have a significant limp. How can I tell if she broke her leg? She let me pick her up and move her leg around without acting like she is in a lot of pain. When I checked on her tonight, she is sleeping in a nesting box which is unusual...