Would you trade a child in if they didn't want to eat their dinner? I'd hope not.

From what I've heard, when on rats, they can often go longer periods without eating because of the extra bulk of the rat. She is probably not hungry. Just don't give up. She will eat when she wants to. Just make sure she is hydrated well(no saggy skin) and doesn't look skinny. If she looks normal otherwise, everything is fine.

With the humidity issue, have you tried just making a humid hide? That way the snake can regulate how humid their environment is by just going in and out of the humid hide. If trying to keep the humidity up is messing up the temperatures, I would say don't worry about it.

The whole not striking thing is normal. She knows the rat is dead, and therefore would rather be lazy and do it the easy way, then put forth more effort than she has to. BP's are lazy, that's why they can go so long without eating. Very slow metabolisms. Just like when bears go into hibernation.

Anyway. If she doesn't want to eat one week, wait another week and try to feed her another pre-killed rat. Your other BP is eating like a champ because he is growing faster than your older one. He needs to eat more often to keep up the weight being burned off by growing. Growing is hard work

Just take a deep breath and relax. Everything is as it should be. Also what's wrong if they get 4 ft? That's very normal. Red tails also go off feed. Would you trade that snake in when it thought it was breeding season and went on a 4 month fast? There's no reason to be so drastic. Your snakes are doing what they do naturally. Everything is good in the world. Breathe.