the e-collar is best for her at this point. She'll learn how to eat and drink and lie down with it on...the body wrap is much harder on them and its tricky to know if its too tight or too loose until they squirm out or lose circulation. If you wrap a cat around the torso, they seem to lose the ability to walk. I have seen this with rats as well, so the e-collar would be best at this point.
Thanks lilspaz. It gets a bit better everyday. She can eat and drink on her own now from a raised dish and the water bottle, and I've seen her lay down a few times in what looked like a comfortable position. It just sucks that she has to be in this thing 24/7, but you saying that it is better than some wraps is very comforting. I was under the impression that these cones of shame are a satanic invention only the worst of people would force upon their babies.
I just let her into the upper part of the cage where her cagemates are, and she tried numerous times to get in the sputnik.

Obviously, that didn't work. She then got into a box with Matilda, who very gladly cuddled her, but she instead insisted on squirming around and having another collar-vs-rat battle, all over poor, sleeping Matilda. This went on for a good 5 minutes, with Matilda constantly shifting around and trying to find a new way to snuggle up to her, before I just took Oreo out or she would have poked someone's eye out, I swear! It almost seems like these playdates make her even more eager and frustrated with ripping it off, and I'm questioning whether they are even helping her out in terms of happiness, because she appears to be more stressed out than anything. (These girls have never had any dominance issues, so I seriously doubt that she feels afraid. Matilda has PT, and Ratatouille is one of the most submissive rats I've had.)
Speaking of Ratatouille, her sister and the one she was closest to, is acting very strange. I don't know if she is freaked out by the whole situation or what, but she has been completely avoiding poor Oreo through all of their playdates, to the point of dashing/jumping away whenever Oreo tried to come near. Just a second ago, when she saw Oreo trying to join her in the sputnik, she sped out like on fire and jumped in the highest, most inaccessible hammock she could find. It's so sad, because Oreo always tries to go to Ratatouille and it just doesn't work.
Would it be a good idea to possibly house them together for the nights or days?
Oreo IS Picaing on that cardboard, gosh dang it, every chance she gets. So if I want them to be together longer than a few minutes, I'd have to put them all in one half of the CN on one level(I don't want Oreo going up and down ramps/levels in this thing), without many nesting opportunities or toys...