I think the size of her current enclosure is just fine, & you did a good job with the "cover"- so good that I can't tell what actual "hides" you've provided- so tell us about that- it matters.

"She" sounds more like a "he" to me- restlessness at this time of year (searching for a mate) with less interest in eating. It would be nice to know for sure what gender, but either way, you'll have to play along as best you can. If this IS a male though, they tend to be fine with smaller meals (nothing larger than a small rat when full-grown).

You might be handling too often for this snake's appetite to kick in- or rather, for the snake to be focused on eating, feeling safe (private) enough & all that. When & how do you offer food? Details?