The choice was obvious? *spoiler*

Am I the only one who thought the choice of who to kill was obvious? It seemed to me that killing the daughter was by far the best choice. Naturally it's still going to be difficult to kill your child, but left with no other option, get rid of the daughter who:
a) Seems to actually be siding with the weirdo little shit making all this happen in the first place!
b) Told her mum to fuck off
c) Can't sing

Ok so b and c are a bit of a stretch, but really it's all about that first point. She knows he is somehow responsible for what's happening, but has professed her undying love for him regardless (as to why that's a whole other question) and plans to run away with him? Even if they get out of this situation, she's absolutely tainted by his weird evil. The only way to fully escape the nightmare and all the consequences of it is to cut her out.

Still makes a hell of a lot more sense than spinning around blindfold ffs