The spirits of the dead... they do not linger long in the hereafter within our world for them to seek out such companionship.

( never mind that, even in death, she will not be like others. she will remain within the world, continuing to guide and watch noctis until their world is finally safe. only then will she rest. )

I suppose there are many that would believe the same. For so long, since I was a small child, I knew it to be that it simply became normalcy in my mind.