In this picture you are looking at her from the back. You can see that her skin is so stretched the it looks like she has no feathers. I am holding her leg, the other is under her.
I carefully removed the skin layer and here is her abdomen. What do you think that yellow stuff is at the back? I bet you are right.
This entire sac here is her ovary or the chicken equivalent. The dark yellow is egg yolk that has actually cooked from body heat.
A better picture of the sac. You see the tube on the left, that is her oviduct. The eggs should have went down it, and made shells right at the end of it before she laid them. These eggs never made it past the yolk stage.
Here is a look inside her body cavity. More weirdness. They look like eggs but are attached to her body walls.
Finally I opened the sac and confirmed it was full of egg yolk and cooked masses of eggs. Possibly she some of the masses are cysts that caused the blockage to start.
So there you have it. Chicken science lesson 101. I am only sorry I didn't know this was happening to my bird earlier. She was acting 100% fine except not laying. I am glad she didn't appear to be suffering from this, although I think we were at that point soon.