(STORY SPOILERS WARNING)
At the final scene, I recommend letting yourself die to see the game over screen, as you'll start over at the same scene, not the whole game. I do recommend collecting all the notes and taking notes of the numbers you find. The puzzle is more simple than you'd think. If you can't figure it out, you can try to google- there's a youtube video and a walkthrough of this game floating around.
The three family... out of all the three, only one approaches and interacts with you directly. Watch very closely to what "it" says, and remember all the journals you took. It will tell you the identity.
(SPOILERS AFTER THIS!)
The lady of the family, Lydia, is the one who lured you into a bait and who tries to feed you. Between her most recent notes and what she says to you, she refers to the mirror as "Master", something the husband doesn't- at least, not in the notes he wrote.