I noticed that there was confusion with my the petrova twins - the one who shouldn't exist fanfiction. Since Adrina woke up in a hospital, but according to her friends she is dead. She is not a spirit or ghost. Later, Adrina will learn more, especially when she meets Esther in season 3.
But if you want to answer now, feel free to check out my Tiktok account, because that's where I post about the story and that's basically where it's already explained. Especially since excerpts from the fanfiction are also for the future chapters.