Thanks for the input guys!
Considering that I just found waste today, maybe she'll be more active tonight. I don't have the bulb turned up very high at all (it's on a dimmer and I adjust based on the temp of the room), so hopefully that is not why she's staying hidden.

Raven01- I usually use CHEs as well on my permanant setups. I only went with the infrared bulb because it was $10 cheaper and I only needed it to work for ~3 months while she's in quarantine. I may end up buying a CHE if I need to use the quarantine setup more often, but hopefully the bulb will hold out for a couple more months until she's ready to move into her permanent enclosure.

I will keep an eye on her the next few days and if she still stays hidden, I'll order a CHE and see if it makes a difference. Her feeding day is on Tuesday, so I should start to see a hungry cruising snake.