She didn't died
but if she died it would of made this manga like almost all the Supernatural love story where the supernatural lover dies of old age leaving the lover to feel lonely till they get reincarnated, just dies leaving there supernatural lover to take care of there kids or just die of old age and make your supernatural lover roam the earth with a hole in her or his heart. it would of bin too cliche if she died. which by the way saying that it would of bin more beautiful if she died is like saying naruto should die before he becomes hokage.
well ,
it was my opinion, I Would have like it more that way
;)
What the hell she that is not spoiler
call me a heretic but I believe the story would be more beautiful if she .....
spoiler alert....
......
.....
died at the end