Where and how are you measuring the temp? You need to measure in the center of the UTH, under the substrate, directly on the glass. It should be 84-85.
The humidity is really not an issue until it's time to shed. Then, cover the screen lid with a sheet of plastic wrap loosely; just lay it on there. Mist the inside lightly about once every day or two until the snake sheds. You can tell she's blue either by seeing the blue belly, dark color, and blue eyes, or by noticing she isn't coming out any more, she's staying hidden, or by noticing she hasn't pooped since her last meal.