Yes, it's kinda confusing, so don't worry. Lucas hinted the fact that she is actually the real Athanasia who was killed by her father, but that was her first life, her second life was in modern Korea, and she died because of an overdose (he said she "gave up"), but then with her magic she turned the time back to her first life (her magic is special, which is messing with her dad), so Jennette is not actually the main character in the real story, it's not even a story to begin with, it was her life, probably the reason why book she read in modern Korea ended in her death and what she supposed happened later (in her knowledge), because she can't know more than what she lived, so the story of the novel ended not much long after her death.
That means that she has had 2 tragic lives before (and she doesn't remember that she's actually the real Athy) & this is her third reincarnation.

I can't stand Athy's struggle & pain. Not only because she got reincarnated third times, but also because she died miserably in her 2 previous life. The fact that she's losing all of what she craved for because of a single little thing really breaks me, i actually cried... She had suffer way more than Claude, nor Jennete nor everyone in this manhwa, i feel so bad for her. I really don't want claude to visualize Jennette as his daughter and being childish and arrogant towards Athie who had been through struggle trying to reach Happiness. If it happen, i'll kill everyone in this planet and then myself or just wish that Lucas will fix the problem (/TДT)/