So unlike some of the other threads here about Serana being missing, in my version she really IS missing. So loooong after I completed the DG questline I brought her to Blackreach just because I thought I could use the help. But eventually I just got fed up waiting for her to catch up to me and I dismissed her while I was in Blackreach. Since I sided with the Dawnguard, she's supposed to be at the fort but she is literally nowhere to be found. And this is practically an in-game month later that I wanted to go get her so she really should have been there by now. And I'm playing this on Xbox so I can't use console commands.

Any ideas?