This book is so weird and I love it SO MUCH; there's so much twisty and enormously creepy echoing going on in there between all the supernatural stuff and the much more frightening reality of their lives. I was thinking about the obscured narrator/identity confusion, and how much it works here when in any other book it would feel contrived - their parents sort of dismiss the sisters as such a conglomerate, their father unable to remember which is which and their mother making hugely arbitrary distinctions, that even though their personalities are perfectly clear to the reader it makes total sense that they would be in confusion.