ALL THE ANSWERS (spoiler warning) :
1. name on the door in the 1st bedroom - amelia, that's the name of the child.
2. go to the 2nd bedroom, where you can find torn piece of paper. after putting the pieces together you'll see a phone number.
3. go to the corridor where the telephone is and call that number. you'll hear a voicemail from a woman who introduces herself as Evelyn. That's the name of the mother.
4. Go to the living room. you'll find a book on the desk showing two pictures with names next to it. read the names next to these pictures and you will notice that one man's name is repeated - it's Jeremy Morris. That's the name of the father.
5. Go to the family tree in the 1st bedroom and write down the names - Jeremy Morris / Evelyn Morris / Amelia Morris. You'll hear a voice and it'll tell you how to put the books on the bookshelf (what to spell with them)
and that's it, hope it helps :)