Indeed. No one's ever seen anything like this. I'd venture a guess that the higher-ups are hitting their heads over the same thing as we are.

All that means is that her origins, creation, and changes up to this point are unclear.

Yet the details of how it happened will not change the fact that she used to be dead, yet was brought back to life with her old memories.

As these two steps created a new being that had her old memories, depending on your point of view, you could treat it as a form of "reincarnation".