Board Thread:Skyrim/@comment-10199795-20130531120916/@comment-26213507-20181105022238

Have you tried attacking her a few times, or ordering another follower to attack? (The latter is for test reasons really, so keep a save handy).

Otherwise, Unrelenting Force could work, or ordering her to pick up something by holding the activate button near hear, resulting in a prompt to get her to do something.