I'm an idiot. Or at least, not electrician-smart. I got a new outlet for my side and installed it. Still no power. I then came to the conclusion that the outlet has to be switched, and that the Power2U isn't compatible.
So I opened up Emily's side and found that one of the black wires had come out of its terminal. Re-attaching it fixed the issue. Moral of the story: make sure that all the wires are secured firmly. Really firmly.