Well, I have been avoiding admitting the obvious for a bit now, but it looks like Persephone is no more.
Not a day or two after my last post about her, when she was so happy and getting colorful, I went to San Diego for the weekend. Sometime while I was away, my cat got up on my bookshelf where Persephone was, knocked over the jar, and either Persephone escaped to some nether region of the house or was ... well, eaten. I had been hoping she would reappear, but it appears that she is long gone.
In the meantime, I am keeping my eye out for another crab spider, or possibly a green lynx spider - they're easier to manage since they don't spin webs. So if I need to clean out the jar then it's easier. At any rate, hopefully I'll find a new spider pet soon.