It's difficult to tell when there's not more information about the story in general. You can't just post and say "hey, what happens in the middle of the story?" when no one knows what the rest of the story is about. Because really, why is the Voice targeting Alice?
Is there a need to kill others in the family? A rise in the tension of the story? Or will the death of all the uncles, aunts, cousins, whatever not make much of a difference to Alice? Does the Voice have any reason to kill the other family members? Or is the death of the parents enough?
There's no good solid answer one can give because we don't know the story. We need more information in order to understand.