BeastBaby
Crater Raker
Ay ya yay, you’ve come home to sick chickens as well? Man, was it far along in the illness? Did you use the same petsitter for the next trip?That's the typical poo from not eating enough.
If it's possible for you, since you said she does eat scrambled eggs, you could try to bring her an extra small bowl with a choice of support confort food daily, ideally before roosting, for a few days to make sure she gets enough energy . Either as a choice, or you can make a mash with their usual food and add stuff in. Some ideas on top of scrambled egg, of things you may have in your cupboards : sardines, tuna or mackerel, crushed walnuts or almonds, cooked whole grain rice or wheat or small pasta, a tiny amount of peanut butter, tiny amount of shredded hard cheese, small pieces of apples or bananas. Everything needs to be smaller pieces than a healthy chicken could eat.
White rice isn't very healthy, but it's something most sick chickens will eat.
And if you have bread that isn't loaded with sugar and additives a small amount can also do the job.
Of course it's best that they eat their usual food...but it's better to eat something than nothing.
If you can catch her easily, I would also weigh her, and do it again in a few days. It's more useful if you know what her healthy weight is, but it will allow to see if she is loosing too much.
I hope the fecal float helps you find out what's going on. It happened to me to find a sick chicken when I came home from vacation and the house sitter hadn't even noticed.
And tiny Chipie...it's a long story ! She has ruling ambitions that are far too ambitious considering her size, and this tends to backfire against her as soon as the younger chickens realise it's all a bluff.

So far I’ve thought to take her egg, apple, and bread (hearty, seedy, organic stuff). I should definitely see if she’ll take nuts! I have leftover chicken meat… would that be a bad idea, if it’s the only thing she eats all day?
She shows interest in their morning mash (which I make using an unprocessed layer feed, so there are whole grains in it) but she then gingerly picks out a dozen grains and calls it good. Not even a thimble full of food.
Huh, that’s a good point about going out before bedtime to fill her crop- I’ll have to make more of an effort at that time.