IN S5 Ep3, Quetsiya Told Stefan that 2,000 years ago, she and Silas were to be married, and they were to take the Immortality Formula. But on their wedding day, she found out that Silas was cheating on her with Amara, her handmaid, who seems to be the Original ancestor of Elena and Katherine, and they are her dopplegangers. She Claims to have given Amara The Cure, then killed her, showing a heart to Silas.
Could Amara be alive?
If she had died, why would have Nature created Katherine and Elena as Dopplegangers to balance the existance of an Immortal?
WE NEVER SAW A BODY!!!! Perhaps Questiya did kill Amara, but preformed a preservation spell on her, like was done with Esther 1,000 years ago after Klaus killed her.