The FernWood Trilogy: Prophecy Twin

Parker had been so immersed in her high school shenanigans that she almost wanted to ignore the new guy in her class. He glances at her intently and she wants to ignore it, really, but then he starts to speak.
Parker Janes entire life changes- arguably for the better- when Griffin takes her back to her lost home and helps her regain her lost memories. All this just in time to learn that she's a major part of a centuries old plot that could erase this world forever.
FernWood, School for the Magically Gifted, is about to change forever as Parker Jane returns to attend.