My mom felt sorry for her, and ended up finding, and buying, a nice big wire cage for her at a yard sale on this past Friday! It had previously been the home of a pair of rats, so the toys are a little chewed, but it has second and third levels, and a tray at the bottom for bedding. My mom was so proud of her find, she came straight over to my house and knocked on my door, just as I was reading a hedgehog book, wondering how we could get her enough excersize!
The cage also came with a wheel, which I was worried she would ignore, and the very first night she spent in her new house, Ambrosia started a self-appointed strict excersize schedule!
Sorry if my story wasted anyone's time, but I was so overjoyed I couldn't help but tell it!