The Mystery Website.

Who let the lock out?

"Never trust a pretty girl... with an ugly secret." - Pretty Little Liars Book Quote

My room is too bright for me, so my mom insisted she design it.
It has pink walls, and tons and tons and tons of photos. There is a grand piano in the heart of it, but I'm not very good. My sister, Caroline, is really pretty with brown hair and wavy hair that hangs over her green eyes like a curtain. She likes to read Pretty Little Liars and The Hunger Games when she's not out shopping with her best friend.
My computer's screen lit up once I moved the mouse.
All the events of the day before fell on top of me.
I was going to visit The Mystery Website.
A post read in the middle of the page, YOUR MOM'S IN FOR A SURPRISE. BUT YOU CAN'T VISIT HER.
It was a cryptic message I couldn't solve.
My mom was at Safeway like she usually was, since we had such an extremely small kitchen. She usually stopped on the way to the grocery store, and went to Rite Aid to get the newest issue of People, which she hadn't subscribed to yet.
What does that mean? I wrote to the user.
The user sent a picture of a lock.
I didn't know why that was there, but I ran to the door and pulled the doorknob, the words Your mom's in for a surprise throbbing through my body once again.
It was locked.
The picture of the lock suddenly made sense.
I pulled the doorknob but nothing happened.
It turned it fifty-seven times. I counted.
It was still locked.
"What the hell?" I screamed as the lock still wouldn't open.
I pulled at the doorknob and suddenly it fell off!
"Damn doorknob!" I yelled as the doorknob smashed against my arm, coming up with blood streaming down the sides.
I put the doorknob on my white sheets and grabbed my phone from next to the computer.
I dialed 911.
There was a pause as the phone connected.
"Hello?" Bleeped the voice at the station where the police lived.
"My doorknob.. Holy crap.. my doorknob fell off!"
There was a pause at the other end of the line.
"Huh? Ma'm, explain."
  So I told him about racing towards the door and trying to open it. I didn't dare mention the website.
The call ended as soon as my story finished.
  A minute later I heard noise as the police car roared into my driveway.
I fiddled with the locket that my grandma gave me before she died.
The police arrived and knocked down the door.
I repeated my story, and they nodded with every two words.
They bought me a new door, and soon Caroline came back, finding me with ice on my wounded arm.
She said "Yes" and everything seemed to click into place.
Caroline. Was. The. User.
But why?