I would love to hear how this turns out. I am wondering if surgery is that necessary, smiling. I have heard people massaging the crop (if it is really hard as described) and putting mineral oil down the gullet of the bird to help move along the massaged food. I think that the best advice right now is what Uno said, to isolate her and not feed her and see if the crop diminishes in size, that would certainly mean that it is being digested.
One time I picked up a cockerel last summer and I was petting his chest. I don't know why, I just thought that the rooster would have nice feathers to touch (I was actually looking for some smut on his body, smiling) and I felt his chest. For fun. I was shocked at what I felt. Having never felt a bird's crop I didn't know what I was feeling for. But I felt this huge mass on the front of his chest. This may sound really stupid, but I have never had cause to feel the crop. So I got kind of worried and I felt this huge mass better. It was his crop. I could feel all the little gritty things in there, clearly the scratch that he has been eating a while before, a few hours later, still not completely gone. This was interesting and I felt the crop some more. It felt very squishy and I could move the inside stuff around and I was squishing this crop, it was very gentle squishing. It was very interesting to feel. Picture a little bean bag, like a hakisak (spelling), that is exactly what this felt like.
I guess this was a learning curve. I know what normal crop feels like, like a squishy bean bag. If a bird had an impacted crop, I think that the bean bag would feel like a rock that has very little give to it.
You say that the contents feeled like they moved around. I don't think this bird has an impacted crop.
When that broody mamma gets off her nest, so she can keep those little eggs below her beautiful and lovely cochin belly, she will need to spend long periods of time before she gets off to eat and poop. Me thinks that the mammas would gorge themselves and their crops would be very full, I think that is what is going on with your gal. Interesting that she pulled out her feathers, this must have been because the weather is cold and she knows she may need extra downy and warmth of extra feathers to help, along with that beautiful belly of Jamaica heated humidity.
Please keep us posted on this, and tell your Son that the little gal will be alright. I don't think you have an issue there at all. Perhaps even this morning when you look at her, you will see a crop that has diminished to a normal size. This was 8:30 last night you made this post, Jen.....please let us know what you see this morning, we are all listening. Have a most beautiful day, CynthiaM.