If her "cool" side actually got to 85*, what did her hot side get up to? I'm concerned about that- she may felt pretty stressed if she was overheated. I'd be way more concerned about actual temperatures than about the humidity, to be honest. Humidity fluctuates in the real world. But a snake that's confined to temperatures that are uncomfortable or even harmful, that's a problem.
Be sure you're taking the temperatures accurately, & inside the enclosure where the snake is. Don't take a thermostat's "word" for it. (I hope you're using a thermostat???)
A 4 year old BP is an adult, & may just feel like fasting a bit- it's not unheard of. They can also feel a shed coming on before we can see any evidence, & may refuse food for that too.
Your snake may also be over-fed- it's easy to do, because our pets aren't as active as they'd be in the wild. There's a chart floating around in other posts here that can help you assess this.
How often are you feeding her? I'd wait at least a week or 2 before offering another meal. Might help to post a pic here too, if you're not sure of her weight -whether she's thin or not?