So I was going to marry Mjoll.
I asked her and she seemed thrilled about the idea. So far, so good...

I asked the priest and he set up the wedding, everything is still good. I got the quest and exited and re-entered the temple of Mara every single hour so that I wouldn't miss the wedding. A bunch of people I have helped in the past showed up. The only problem, she didn't. Never showed.

Eventually I failed the quest. What's worse is I haven't seen her since. She was my follower at the time but she never came back to follow me again. And I have searched every inch of Riften (including the Bee and Barb where she stays and Aerin's house) and she is nowhere to be seen. What the heck happened?