It sounds like you are doin pretty well. If you have the temps at 92 and 80 and its stable then you should be doing fine. What is the ambient temp? The humidity fluxuation from 40s-70s should probably be controlled. Most people shoot for like 55, and some push it up for sheds. This is the hardest part about a glass tank, a lot of people cover the lid with vinyl or foil as a way of holding heat and humidity in.

Depending on the size of the snake, some might argue that 30g is too large, but if she is eating I would think its ok.

I wish I could have more confidence in my answer here, but I am new to snake keeping as well and struggled with a glass tank for a few months so now I just use a tub. But I have done a lot of reading on the forums and these are the definite basics that I have learned.

maybe post a pic of the setup to help the pros get a better feel for it...

Good Luck!