Thank you for asking, gbranson. That's a great question. My answer would have to be two-fold. For one, I once was a six year old girl with a dramatic flare but Andora is not meant to be "me". I feel a connection to her as if she were almost real.
Before I even wrote about Andora Fiona Grossman her name just came to me and it's almost like I started writing effortlessly about this little girl I already knew. It's weird, I know.
And, number two: I grew up reading Ramona Quimby and later on fell in love with the series of books with Junie B. Jones. When I wrote Andora Fiona Grossman about ten years ago, I already had "her voice" before I even started reading Junie B. Jones.