I think the nest sitting is coincidence. There are so many factors in what causes a bird to go broody. For that one, I would use a broody breaker crate, also referred to as 'chicken jail" (see article below- at the end).
https://www.thehappychickencoop.com/6-ways-to-break-a-broody-hen/
I think your worm sightings are probably die off from the treatments. With the slower/lower dosing, die off may be slower. Once you complete the treatment I would get a fecal done to check. You can use a mail in option if you don't have a vet that will do it.
https://www.amazon.com/dp/B000J5SOZ4/?tag=backy-20
https://www.thehappychickencoop.com/6-ways-to-break-a-broody-hen/
I think your worm sightings are probably die off from the treatments. With the slower/lower dosing, die off may be slower. Once you complete the treatment I would get a fecal done to check. You can use a mail in option if you don't have a vet that will do it.
https://www.amazon.com/dp/B000J5SOZ4/?tag=backy-20