Board Thread:Q & A/@comment-4097293-20150226082755/@comment-26235944-20150523025327

There was another thing... When Adalind made her potion to remove Nick's powers...she used some of Juliette's hair. Adalind went to the trouble to go to Nick & Juliette's house, remember, got some of Juliette's hair...and then got into a fight with Renard there, when he showed up and asked her what she was doing. Elizabeth said that they had to recreate exactly what Adalind did, but in-reverse, for it to work. But...Elizabeth didn't use some of Adalind's hair.

Maybe Elizabeth used some of her own hair, as a substitute for Adalind's hair? And maybe that is why Juliette turned into a hexenbiest.