PLL Theory: Alison's Twin Courtney DiLaurentis
In the books, Alison has a twin sister named Courtney. After watching the first season again and the recent Halloween train episode, I've noticed a few clues. Here is Alison in the first episode in the barn the night she disappeared:
Here is 'Ali' in the flashback with Garrett and Jenna in the latest episode:
Notice the hair. This might seem insignificant, but really think about it. Alison ALWAYS has her hair curled, even when she's being Vivian Darkbloom.
Also, look at the bracelet, the name on it ends in an 'ey' COURTNEY!
My theory is that Courtney switched places with Alison in this scene, and got the idea of how to kill Alison from what happened with Garrett and Jenna:
This is what sparked Courtney killing Alison. She knew Jenna already thought 'Alison' was dead, and the incident inspired her to do the same to the real Alison and thinking she was dead, buried her sister alive.
