I dunno. I still gotta go with the Mean Little Girl theory. There had to have been some reason the Hoodoo Nanny was keeping her away and Rose continued to do so for so many years. She must have been causing trouble from the get-go. She not only killed innocent folks who were just trying to do their jobs, but she was ready to kill her nieces and/or hold them hostage until her sister agreed to give up her own life to keep her company.

She may have been a sad little girl ghost who died young and tragic and just didn't want to be alone. But then you get into that slippery slope of "Well, Jason Voorhees was just a poor little kid who drowned", "Candyman was just a tragic victim of a lynch mob", "Hannibal Lecter was just a little hungry", etc. Nah. She was a Mean Little Girl!