She's only Hylia reborn. Just a reincarnation. She's not the actual one who defeated the Demon Lords in ancient times. But I think that's really awesome that she in fact is connected to the Goddess. It's just sad that she has to sacrifice herself in some sense.
wasn't quite sure about reincarnation or not , also Zelda seemed to know about it but I could be wrong
Well, she was probably awakened later in the game.
I feel so stupid now wasn't thinking