Is she having difficulty breathing and is her crop emptying overnight?
I would make sure her crop is emptying. Feel for an egg, but likely if she's pooping then she's not bound, but her stance shows she's in distress.
Where are you located in the world?
Corid is for treatment of Coccidiosis, it won't hurt her, but if possible, taking a sample of poop to your vet for a fecal float to see if worms may be an issue would be a good idea as well.
Work on hydration and I would get some calcium into her too.
Yes, you should be able to see lice and mites with the naked eye. Look around her vent, face, under the wings, etc. for any bugs.