Update:

Thank you guys for responding!

Since posting this, I've kept a close watch on Ygnizem and she's pooped and peed already (so I guess that means she ate something while she was on the loose). She's been soaking a lot and it looks like she's about to go into blue sometime soon. I've fed her a large mouse and a hamster, the latter so she can recover whatever fat she's lost.

As for handling, I've only tried putting my hand in her new enclosure and she's stopped hissing and striking already. However, when I lifted her out one time I saw that her abdomen (near the vent) was swollen and tender. I wonder what this is