Witch or Shadowhunter?(TMI/HP crossover)

The Mysterious Letter

Two years later

  It's a Sunday, the only day I get to sleep in. My parents go to church to seem normal to our mundane neighbors, but they don't make me go. Grace is coming over later to celebrate her birthday. With a sigh, I climb out of bed and get dressed, yawning. I step outside for some fresh air, and an owl lands on top of my house. That's weird, owls don't normally come out during the day. I sit down on my porch, ignoring the owl, and wait for Grace. The owl ruffles its feathers and takes off, dropping a letter right next to me. I pick it up, confused. It reads:

Miss. N. Nightcross
The upstairs bedroom
67 Brewery RD
Plumstead
London

  I reread the address several times until Grace walks up to me. "What's that?" she asks, pointing to the letter. I shrug, "no idea, lets go inside." Inside, I place the letter on the table and lead Grace to the living room. I sit down and she switches on the TV. "Are we really just going to watch TV until my parents get back?" I question. "Yup, you know my parents won't get one," Grace replies, plopping down next to me. I giggle, "couch potato!" She lunges at me, and I knock her to the floor, "that can't be your best!" Grace grabs my legs and pulls me down beside her, leaning over me. Her hair in her face, she glares at me, "no fighting on a Sunday." I groan, wiggling, "but Grace, you know I love fighting you, its so much fun!" She rolls off me, starting to giggle, "well, you no longer look like a demon when you smile." I sigh. After I had grown in my top front teeth, I lost my bottom ones, keeping the demon look. But now my bottom teeth had grown in, and there were no more to loose. "Do you ONLY fight demons?" I ask, sitting up. Grace smiles, "yup, that's what we're supposed to do, dumdum." I ignore her comment and stand up, grab my letter from the table, and sit on the couch to open it. Seeing what I was doing, Grace sits next to me and peers over my shoulder at the letter. I shove her slightly and read it aloud.

"HOGWARTS SCHOOL of WITCHCRAFT and WIZARDRY
=========================================
    Headmaster: Albus Dumbledore (Order of Merlin, First Class, Grand Sorc., Chf. Warlock, Supreme Mugwump, International Confed. of Wizards)
Dear Miss. Nightcross,
     We are pleased to inform you that you have been accepted at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment. Term begins on September 1. We await your owl by no later than July 31.
     Yours sincerely,
  ʍíղҽɾѵɑ ʍϲցօղɑցɑӀӀ
  Minerva McGonagall,
  Deputy Headmistress"

  I look at Grace, blinking in confusion. "Do you think its a joke from some warlock that has a grudge on you?" she asks, but I shake my head. "Its not fake, I can tell, but what is Hogwarts and why did they send me this?" I reply. We both shrug and decide to wait for my parents to return. We watch different shows on the TV, some more annoying than others.

  When my parents open the door, Grace and I quickly turn off the TV and open my Shadowhunter crossword book to a half finished puzzle. My parents walk in and smile at us. I look up, "hey momma, what's Hogwarts?" Both my parents look confused, so I hand them my letter. They read it silently, brows furrowed in confusion. Turns out we were wrong to think my parents would know. When they're done, they sit down on the couch, thinking over the letter. Then momma looks at dad and whispers, "we must see the silent brothers." By the Angel, no.