Well, alright then, there was stuff I was missing.
I liked it. I'm not over-the-moon about it or anything, but in the end it was all pretty well done. I do like when a character has a revelation that I have seen coming for ages, but then that is not the final truth.
The mood carried well throughout the whole piece, which I always appreciate. It was eerie and felt full of secrets. I liked both Lucy and Kit.
As an attempt to piece together the ending:
I questioned the identification of the twin in the park, but had nearly forgotten about it up until I started realizing that both Lucy and I were barking up the wrong tree with the idea that Helen was the living sister. The groundwork was there, really--Aliese was weird about Helen from the beginning, and looking back at it I should have seen a bit more than I did, but I was so focused on sardonic Helen being maybe a crazy person I never really thought about it. And the character most insistent on Aliese being such a good person was Lucy, who outright admits she practically worships her mother and who I had pegged very early on as a pretty unreliable narrator in that she doesn't pick things up well.
I assume the whole pregnancy thing with Aliese acting like this was her first child was due to the fact that this was the first time she was having a child with someone she apparently cared about?
I definitely knew pretty early on that Helen was sleeping with Frederick; that seemed obvious. Though what that meant I couldn't quite fathom. That meant I should have realized that if Helen was the dead one and she was pregnant, it meant the child was probably Frederick's, but I am not completely sure I managed to overtly make that connection.
It was unexpected in chunks and probably could have come together a little bit more clearly than it did (maybe by having other people suggest that Aliese's behavior was questionable, even if Lucy immediately denies it?), but I didn't find the ending too outrageous.