When Earth is threatened by a cosmic war, a young woman with newly-awakened powers becomes mankind’s only defense.

Isn't this just 'Dark City' with a female protagonist?

I wish I could offer better suggestions. At least for me, I'd love to follow her as she awakens to her powers. It must be thrilling and terrifying. Maybe with no mention (or a vague hint) of a greater cosmic war?

You got me there TimmyElliot.

I think the originality will come when I actually construct the mythology that goes behind it. I have no idea how to put it in the actual logline without distancing the agent or manager from it, but I also don't want the story to be too familiar, which seems to be a tough line to straddle within the apocalyptic genre.

What if I changed cosmic war to an interstellar, holy war with gods warring over who gets to reclaim the earth for his or her self? I want her powers to be spiritual in nature anyway and the story to be a question of what if God is a group of alien beings.