Slytherin? Ravenclaw?

Set after the war, in between the last chapter on Deathly Hallows and the Epilogue.What if Draco had a twin? What if the Sorting Hat had some trouble? This is my first book, so no hate please. Polite critics welcome, though. Be warned: the Epilogue will be different in this to what J.K. Rowling wrote. Disclaimer: I don't own anyone other than Liliana, the rest are J.K. Rowling's.