Maybe it's Pepper's coping mechanism...to subconsciously replace the people in the ugly asylum in her mind with familiar faces. Why then would she have chosen Elsa, who was so kind to her, as a Sister Jude replacement? Was she disappointed in Elsa for taking her away? Perhaps she saw Sister Jude & Elsa Mars both as the only authority figures in her life? They were both more than a bit unorthodox. But Jude was so extremely cruel until the end of "Asylum" (a transformation that Pepper never got to witness).