What did Abby mean when she said she wasnt a girl?

What does that mean? I heard she was born a boy but was turned into a girl? Is that what happened because that almost freaked me out. Did they mean she turned into a girl or in the book she was a boy but turned into a vampire and stayed a boy.|||LOL|||It would help if you would let us know what the hell book you're talking about, drip.|||Abby,who ?what book?