Also put ideas of books that would be appropriate for an 11 year old girl who is Christian.

So, science and harry potter books are out of the question?

Everyone should read The Great Gatsby.

I dont know about suitable because i've never bothered about that kind of thing myself and I read a lot of books that were not "suitable" when I was a kid so i'll just give you a list of some of my favourite books and writers and my view on what kind of age group I think they are suitable for you can look into them and make your own mind up. I'm pretty sure a lot of them wont be your cup of tea but are worth a look.

The Hobbit and The Lord Of The Rings - JRR Tolkien, Epic quest fantasy, the Lord Of the Rings can become quite heavy going in places but is rewarding and worth the read

Neuromancer - William Gibson, one of the first "Cyberpunk" Science Fiction books written in 1984, long before the Matrix, the Internet and Laptops and its frighteningly prophetic, if you like that his other books are worth checking out

Carl Hiaasen writes pretty good comedy crime fiction, most of it is aimed at the adult market but he has written some books for younger readers

Terry Pratchetts Discworld books are funny, A Colour Of Magic and The Light Fantastic etc

Fear And Loathing In Las Vegas - Hunter S Thomson, anything by this guy is worth reading it's nearly all semi autobiographical, although when you read about his adventures you realise there is no way that man could remember doing all that stuff so some of it must be fiction. Fear and Loathing is about his demented drug fueled road trip to Las Vegas, probably his most famous work (probably for when your older though!!)

A Clockwork Orange - Anthony Burgess. Probably another one for when your older but its worth a read, set in a dystopian future its the story of Alex a violent hooligan who gets caught by the authorities who try to cure his antisocial tendencies by using "questionable" means.

Hope this was helpful and I don't know if any of these will suit you but I read them all when I was around your age and a little older and I have copies of all of them on my shelf and have re-read them all.

Fifty Shades of Gray lol. .