Just because kids, and animals are not stupid, and may even know better, doesn't mean they won't get a brain fart, and do something stupid.
You mentioned that you had been giving a verbal command, on a daily basis, to the roosters, so they wouldn't fight. Maybe you forgot to say it that day...
For years I've been drooling over the Sweeter Heaters, but they're so dang expensive. Last year, I finally got 3 of them, one for each coop that I normally use. They are safe, and are not power guzzlers. For the record, they do NOT heat the coop, but they do heat the birds. The way you test...
I occasionally give mine canned cat food, especially when they're molting, so they get animal protein. I find the animal protein improves feather quality. Mine LOVE the cat food, so I'm not surprised that Scarlett took to it. I'm sorry both of you are having to go through this.
You should still be able to buy the injectable penicillin without a prescription. Try here too: https://jedds.com/collections/cage-aviary-treatments-antibiotics
Fingers crossed for your eggs, and for Cricket. Yeah, make sure she gets the Duramycin for a week, to help stop any internal infection from the broken egg. Hopefully you caught it in time, and she's young, so the odds are in her favor of pulling through.
"I have started saying things went north, not south. I take exception to the phrase for things being all mucked up being associated with us down here, Cheryl! LOL."
I had to chuckle after reading that. I agree wholeheartedly.
It sounds like it's time to do some separating, before someone gets hurt, even if it's not the best of timing. Um, for the record, the ONLY time things ever go south, is when the timing is BAD. ROFLOL.