That is quite strange. One easy way to fix this, or at least it should work, is with NRaas MasterController, if you have it. (You'll need both the base mod and the Cheats add-on.) Click on the sim and select NRaas > MC > Intermediate > Occult: Remove. That should remove any data related to the sim's fairy state.
If you don't use mods, can you switch her to human and save her as a template in CAS? Changing a sim from occult to human in CAS (or vice versa) isn't a good idea, as the features don't always get deleted properly—that's how people end up with "humans" with wings or vampire thirst. But a freshly saved CAS template might work better. You could quit, reload, open CAS, load the template, and then adjust the sim further if you wanted.
