There's a special kind of chaos that only comes from a Craigslist chicken deal, and this rescue is a full-on feather-less soap opera. Between the sketchy seller who went silent at the mention of other birds, the hen with a swollen belly doing the penguin waddle, and the poor girl with an eye but no pupil, this is less "farm fresh" and more "fowl play at the county fair." We've seen our share of mystery birds around here, from Cluck-tastic mystery: 7 feathered friends, 10 weeks, zero clue who's who to Feathered Friends, Fowl Play, or Just a Hen in Disguise?, but this situation takes the cracked egg.
Our take? You did the right thing by quarantining those birds immediately, and that alone deserves a cluck-tastic round of applause. The moment that seller got weird about your existing flock, your gut should have screamed "contamination," and you listened. That instinct is worth more than any fancy spray. Now, about that spray: Premo Guard is a decent start, but lice eggs are stubborn little buggers. You'll need to reapply in about a week to catch the hatchlings, and you'll want to treat the coop, the roosts, and honestly, your own shoes before you walk near your original 16-week-olds. Those babies are still growing, and their immune systems aren't ready for this kind of drama. As for the egg-bound hen, the warm bath is smart, but if she doesn't pass that egg within 24 hours, you're looking at a vet visit or a gentle, well-lubricated assist that you should research thoroughly before attempting. Egg binding is no joke, and while the cooked egg and chick feed mix is a nice touch for nutrition, it won't fix a stuck egg.
The missing pupil is the wild card here. It could be a birth defect, an old injury, or something neurological like Marek's, but you're right that the lack of distortion points away from Marek's. Keep her separated and watch for any head tilting or balance issues. If she's eating and moving fine, she might just be living her best one-eyed life, but that closed eyelid is a flag you should keep flying. And that rooster? Firm and fat while his ladies are skinny and lousy? That's a classic sign he's been hogging the feed and probably the warmth, the little feathery jerk. Treat him too, or he'll be a walking lice motel for weeks.
Here's the concrete takeaway: you've got a 10-day window to break the lice life cycle, so mark your calendar for a second spray round, and don't skip the vent cleaning on every single bird, even the fat rooster. And if that egg-bound hen doesn't produce by tomorrow morning, skip the internet and call a local avian vet. You've already saved these birds from a sketchy handshake; don't let a preventable parasite or a stuck egg undo your good deed. Keep us posted on the one-eyed wonder, because honestly, we're invested now.