I may be confused with Ballet Shoes but I definitely read a book in my teens (1980s), borrowed from school library. The only things I remember are that there was ballet involved, it was at least partially in Russia, sure there was a mention of a White Palace. There was a bit of teen romance and I think the boy was called Sebastian. Maybe I am muddling up a load of books but I just have the feeling that there is a book out there somewhere I once read and loved.
Lost Classics of Teen Lit: Name That Book! 