It's all gone wrong.

Moon had been sitting in the house nest box. She got a decent examination on the first day and laid an egg that day. I posted a picture on one of these three threads. Absolutely no problem. Egg delivered fast with no sign of discomfort. I had a look at her vent while she was laying the egg. It looked normal.
She's been sitting for three days now. The plan was to put her back in with her tribe this evening. She hasn't been able to defend her nest, her sister Tap throws her out so she can lay, as has Tackle and Mel. Fat Bird just throws her out anyway.
This afternoon she started to look very uncomfortable and was straining as if she wanted to lay an egg. I got her out of the nest box and watched for a while. At first I couldn't see an egg but it looked to me as if she was egg bound. Worse still, above her vent was swollen and looked like what we would call a hemorrhoid. She was definitely egg bound and trying to empty her intestines and lay the egg. All very messy. I got the coconut oil warmed up and with a bit of careful oiling and some manipulation from outside below her vent (you can tip the egg to allow the oil to reach any dry spots like this) she eventually laid the egg.
As I've mentioned, she normally lays dark brown egg. This egg was almost white with brown patches so the paint booth is faulty. Applying the colour to the shell is the last process before the egg is laid. The shell was strong enough to survive dropping onto the concrete floor so calcium wouldn't seem to be the issue.

The bulge; I'm going to call it a hemorrhoid. looked pretty sore and the top edge where there are follicles was very dry. It's not a prolapse. A prolapse is when sections inside the vent push out. This is something else.
Anyway, once we had got the egg out she looked much more comfortable and went back to the nest. Somehow when getting the eggs arranged underneath her she managed to break one. This is a nightmare. The nest has to be stripped out and cleaned, preferably before the hen gets her underside covered in sticky egg. Once covered in stick egg, more eggs stick to their underside and because as they adjust position any eggs stuck to their underside become fragile wrecking balls and more eggs get broken.
Moon is now in the pet carrier on towels with three eggs to keep her stress levels down. I've cleaned and disinfected the area around her vent and applied some hydro cortisone ointment to the bulge. I'll get some cream for hemorrhoids for her tomorrow.
The thing is, what is a broody hen doing laying an egg after three days of sitting having not laid in the previous two days?