Vanished

I...I don't know what to think.
I'll start at the beginning I guess.
Ok, so I arrived at mum and dad's a few hours after my last post, spent at least an hour trying (unsuccesfully) to calm my hysterical mother down. Eventually she just sort of...deflated I guess, collapsed on a chair and pointed to Megan's room. Curious, I walked in and was immediately greeted by a face full of Operator symbols. It was like she had gone and taken all the the paper out of the printer (which she probably had), and then decided she wanted operator-symbol-wallpaper. There wasn't a centimetre of clear wall anywhere. And just to top it off, her desk was covered in drawings of Mr. Tall Pale and Faceless himself, his tentacles making him look more like a giant spider than a person.
Oh and her journal is full of creepy-as-shit rambles and dreams. There's some pretty messed up stuff in there.
It was like something out of Seeking Truth.
I honestly have no idea how to take this. either,
a) She ran away after spontaniously redecorating her room
b) She was abducted after spontaniously redecorating her room
c) Slenderman is real
Ok, c) is highly unlikely, but you never know. After god-knows how many hours combing the neighborhood looking for her and finding nothing, coupled with the state of her room and her weird journal entries, you have to wonder...
Guys, I need advice here. What should I do?? Did she just run away? If it is Slenderman do I continue looking for her and risk bringing him after mum, dad and I?
I'm going to go search through her room again and see if we missed anything.