At least Becky finishes the job
In most/all horror movies, the protagonist eventually shoots/stabs/knocks out the antagonist. They then run off and end up facing the antagonist again when they could've taken care of business when they had them on the ropes.
My girl Becky makes sure the job is finished. I find it extreme that a young girl is capable of such acts, but I think this movie is not to be taken too seriously. I guess you just gotta go with it. A little more background on why she is the way she is would've been nice though.
I liked it.