If they are molting you will see a lot more than a few feathers, even if it is what they call a mini-molt. The longer a hen lays without molting after a certain point they slow down laying and the quality of the eggs can drop. With commercial flocks of hybrid layers the point where productivity drops enough to make them not profitable is often around 13 to 15 months of straight laying but you don't have those hybrids. Chickens evolved to lay eggs and raise chicks in the good weather months when food is plentiful and take the winter off and molt. But since we have domesticated them we've messed up their regular cycle. Now you get some pullets that lay throughout the winter their first year and hens that come back into lay when they are finished with their molt instead of waiting for spring. Their bodies wear out with continuous production and need to take some time off to rejuvenate.
It is possible but not certain that your hens are taking some time off to recuperate. They may or may not go through some kind of mini-molt, then come back laying like blockbusters until the fall molt. It could be something else.
I agree once a hen starts acting sick she is in pretty bad shape. It could be a lot of different things. The only first aid I'd suggest is to take a medicine dropper and put some sugar-water on the tip of her beak so she can drink it if she will. That might give her enough energy to start eating again on her own. Do not stick it down her throat, that could drown her. You can dissolve some sugar in water or use hummingbird liquid. Yours are probably pets and I'm pretty cruel and ruthless, but I would not go any further than this.