The only thing I don't understand is the February calendar thing.
Can someone explain this to me? Kat is shown at the beginning being led outside by her "father" to a car accident, presumably with her mom in the car, right? Then she's shown crossing out the days on her calender leading up to when her parents pick her up. Valentine's Day is shown on the calendar, so it's obviously the month of February.
My question is, when did these take place? The school is supposed to be on WINTER break, right? Isn't winter break in December? Also, what was with her being led outside to the car? Was this a dream sequence, maybe brought on by the demonic presence inside her to let her know her parents had died?