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@Weeg has not been on since last year, but hopefully she may get notification and give you an answer.
If your hens has a prolapse, it's important to get Extra Calcium into her daily until she heals up. You can find Calcium Citrate with D3 in the vitamin aisle of stores like Walmart, CVS, etc. Give 1 tablet daily, just pull down on her wattles, pop the tablet into the beak and let her swallow.
Keep any exposed tissue moist with honey, coconut oil, anti-inflammatory cream, vaseline, etc. so it doesn't dry up and turn necrotic.
Hopefully she was able to expel the egg without the contents getting inside the reproductive system. If it did break inside, then I'd give an oral antibiotic to help prevent infection.