Description pulled from GoodReads:

Perfect Amy Candler tries hard to blend in with everyone else, but then she comes face to face with someone who looks just like her--someone who is another Amy. The two girls look identical, and Amy expects them to have identical personalities. But she's in for a big surprise. The other Amy is determined to stand out from the crowd. She's determined to grab the spotlight, even if it means squashing the competition. She's determined not to have a look-alike, and she wants Amy out of the way. She's...well...evil! Amy must stop her, if she can.