'Phoebe Who?' by Emma Harrison

A battle's finale, one sister lost --
Enemies disguised as friends, aim to cross.
Two sisters must remind her what she can't recall:
To bring her home safely and restore power to all.

Phoebe is exhausted -- between work, demon fighting, and helping her sisters, she has no time for herself. When she wakes from a battle not knowing who or where she is, Phoebe gets her long-awaited getaway and then some. A stranger named Aura promptly finds her and takes Phoebe into her care. There's something off about Aura and her friends, but Phoebe ignores her instinct and tries to settle into this new, relaxed lifestyle.
Meanwhile, Piper and Paige fear the worst. They scry for Phoebe, but she is nowhere to be found. Not only have Aura and her friends put a cloaking spell on Phoebe, but they have also reintroduced her to magic, taking her on "missions" to steal protection charms from good witches. Their latest mission? Convincing Phoebe that Piper and Paige are evil and need to be rendered powerless. Will Piper and Paige be able to find Phoebe -- and help her find herself -- in time to restore the Power of Three?

Published by: Simon & Schuster New York

Notes:
*Featuring Piper, Phoebe and Paige