Can someone explain to me what happens in the end of the horror movie "the silent house" aka "la casa muda"?

i don't get it. why does she kill her father? why did she have to kill her daughter? why did she kill the other guy nestor (i guess the father of her child). if she killed her father how could she have done it if he was upstairs and she was downstairs? when she was hiding in the room who was the guy she was hiding from who had the knife? why did she run away if she was the killer? why did nestor jump at her when she was in the dark taking pictures? what is up with all of the pictures on the wall in the end? please explain to me. i don't get it at all. thanks