A good movie, it didn't really hit for me but the ending was great. The way Enid broke down and ended up being the killer was pretty good. Her trying to technicolor her life and the interspersed cuts to real life were horrifying and wonderful.
I do think Enid probably killed her sister and then lost the memory of it. I wonder if her parents then tried to cover it up to protect her as they seemed like they had moved on from Nina's death.
Enid felt so much guilt that she lived her life trying to protect the public.
I'm usually a sucker for this era but this movie didn't really do it for me.