She isn’t the originals Bea cause she’s from a different world and that is the world from inside a novel she read when alive in her previous life. This is why she know the invents than unravel.
But the soul in Bea’s body is most probably the original Rae.
I think this is a bit of bad wording. This line should mean that she thinks Bea knows that the soul in Rae is not the original Rae, not that Rae and Bea switched specifically. The “We” refers to the two souls that were in Rae’s body. After all, Rae does not know why Bea wants her dead, or why she’s acting so different from the book. She has no way to know Bea was OG Rae
Eunha(our FL in current Rae's body) is the original Bea. Her soul was supposed to go to Beatrice but OG Rae got her hands in black magic and swapped their souls.
Wait. Does this chapter means that Rae knows they switched bodies? Does this mean she knows she's the original Bea?