Demi Mikaelson is the forgotten original, she is the twin of Klaus and is just as bad as him although the twins do not get along so well. Demi was with her wolf pack when Rebekah came to her for help back in Mystic Falls. Demi goes back to Mystic Falls but family feuds arise when she mets Klaus again.

Dear Diary, Love Sucks. Nina Gilbert is Elena's long lost sister, both look like Katherine about both are mistaken for Katherine. Damon Salvatore, believes Nina is really Katherine and takes her captive to the boarding house. After realizing she is a completely different person, he decides to keep her until he knows why she has the same looks. Along the way, Stefan and Elena move back into the Boarding House and the sisters are reunited. But just because they're playing happy families for a few moments, doesn't mean that they can escape the world of vampires, werewolves and originals...because Klaus is soon coming. Damon and Nina are developing feelings for one another, but neither knows what to do. They don't have anyone's approval, and Nina already has Tyler Lockwood and Matt Donavan fighting over her. But is it Damon she loves? Or will she follow in the same footsteps as her sister, abandoning Damon into lonliness? Vampire Diaries Fan Book, Based On The TV Programme

Alexandria Salvatore. Damon and Stefan's Little Sister. She's 15, she's beautiful, and she's of course a Salvatore. Her brothers thought she was dead and gone for good. They missed her terribly and they want her back. But, what happens when she actually does comes back? This is the story of what could have happened if the Salvatore Brothers had a sister.