This isn't a 'lost classic' in Britain, it's a pure classic. And her name isn't Cassie (she's never, ever called that in the book - don't dumb down, it's self-defeating as kids who read this will have to get used to her name) it's Cassandra. People here name their daughters after her. It is an amazing book and a rite of passage read for a great many British girls to this day. I don't know that every American family will understand it - but I hope you do in the same was that we here understand To Kill A Mockingbird. Something from a different place and a different time, but that speaks to all of us. Enjoy.