My dd7 just finished Matilda and it's now one of her favorites. She also liked The BFG by Roald Dahl.

She's also enjoyed The Penderwicks, The Secret Garden (took her a while to get into it, but once she was, she liked it), The Fire Within (a dragon series with a little girl in it), Charlotte's Web has a female spider (but consider The Trumpet of the Swan also, which is my dd's all-time favorite).

She's reading Because of Winn Dixie right now and is enjoying it.