I'm afraid to say this in case I jinx it, but Jessica slept in her bed by herself without Mommy for the last 2 nights. She'll ask me a couple of times in the night to come "upstairs" (which is what I've been calling the top bunk), but I'll truthfully tell her I'm too tired, and we both go back to sleep.
I gotta admit, while I was very hopeful this would work, I wasn't really sure. Now I just have to figure a way to get back to my own bed, which is a lot more comfortable than the bottom bunk. But I'll take what I can get.