I agree with @DobieLover that is not an egg. I would post in our Emergency forums on this. I don't know it that was something she ate, or even possibly has an oviduct infection. I hope she is ok! https://www.backyardchickens.com/forums/emergencies-diseases-injuries-and-cures.10/UPDATE!!
Sunday afternoon, Pickles became pretty lethargic and stayed in one spot until dark. I took her inside the house (in a dog crate with a basket filled with hay in case she ended up laying) and was about to do the Epsom salt 20-minute soak... I fed her a mix of crumbles sprinkled with 1 calcium pill and 2 baked & crushed eggshells. Seemed like a burst of energy came over her after she ate half of the first serving (I used the quail base for a quart jar) and she cleaned it out so I gave her another serving. I also gave her some hydro hen and this was the most I had seen her eat or drink since before 10/1. She was exploring in the house, Frenchie (the cat) came over and said hi and she wasn't scared or weary, she actually came up close but then the cat got scared and ran. She tried to lay and was moving hay around in the basket but then she kept getting up, then she started pecking me. I left her alone for about 20 minutes to see if anything would happen but she just kept eating and drinking. She seemed lonely so I ended up taking her back out to the coop with the girls and they were all happy to be reunited. She explored the newly renovated coop and then slept on the new roost we built.
Monday morning they were all happy and energized, each left a present for me except for Pickles. A few hours later, I was inside the shed cleaning and noticed she was in the coop pacing back and forth. I left at 11 am to run some errands and pick up some supplies. I get back at 12:30 and unload stuff into the shed and she's just getting out of the box... She runs out to the run and sure enough, she finally laid an egg! Although I'm not sure if I should even call it that. Because this is the softest I'd ever seen (out of the other 4 she did previously) and it is oddly colored. I wonder if it had been stuck in her this whole timeand could she have more? Would she need antibiotics?