I thought this series was pretty good so far, granted, i skipped books 2 and 3.... i didn't realize this was part of a series! I got books 4 and 1 from my cousin a long time ago, along with a whole box of books, and i read them a long time ago too. So in all that book confusion i read books out of order, and randomly find my childhood books on Goodreads! Anyway... from what i remember, Amy was some scientific project and has like a crescent moon mark on her or something. She was made to be an elite superhuman, and the project was cancelled. every amy was supposed to die. Her 'mother' smuggled her out and she remains a perfect Amy. Now there's tons of them!