I've tried room humidifiers. I actually have one in there now but it's barely doing its job.

I don't see any burns, or anything that looks like burns.

As for retained shed goes, when I got her from an expo, I COMPLETELY checked her out, she had a little bit of loose shed which I removed with a wet cotton swab when I got home. She hasn't shed in my care (but looked like she was about to).

I don't see any signs of scale rot.

Do you think it might be dehydration? I usually put fresh water in every day, and completely clean the bowls every 3 days, but I have never seen her drink.

As for moving my snakes into another room (which you might have suggested next), not going to happen. I'm a highschool student in a 2 bedroom apartment with my father and he's already said I can't move the snakes into a different room.