Hi! I don't know if I will be of much help here, but I might be able to give you some advice.
I've never had this happen, and I'm not a vet, but I read about this. And also, I recently had a trouble with a hen who had a prolapse, and she is fine now. I know they are not the same thing, but they can both cause/have to do with egg laying problems.
Here is a thread about it...this person thought their chicken was laying internally, and it turned out that that wasn't the problem.
We have been giving all of our hens coconut oil (including the one who had the prolapse) because it is supposed to keep them lubed up, and keep their laying process smoother. Plus, it's antibacterial and antimicrobial. So giving your hen coconut oil might be beneficial.
Also, from what I understand, you want to keep infection out. If you want to not use antibiotics, you could use garlic and oregano in her water.
If you want to stop her laying process until you get it figured out, you could put her in a dark spot. Make sure she is in the dark for at least 16 hours a day, and she probably won't lay. My hen who had the prolapse hasn't been laying because we have her in a dark room so she can heal. That might give you a chance to sort out what's going on, or possibly allow her to heal.
I'm not an expert on this, I really don't know much about it. So if someone comes on here with more expert advice, you might want to listen to them more. But good luck with her and keep us updated!