I don't know how this happened but after a couple days of having mjoll in my lakeview manor, she started doing this sort of penguin waddle. She gets stuck in weird places and she just continues doing that WADDLE. I think i ran into her but like i said i don't know how this happened.
She did that to me. To stop it, I had to kill Aerin, loot his body, pickpocket her, and run into to her. This causes her to die, and respawn in a very fast motion, taking 0.0000001 seconds to repsawn and die. It will stop after that.