RE: A teen mysteriously cured of terminal cancer becomes the centerpiece of a war between supernatural factions that are hellbent on procuring a miraculous, prophetic pregnancy that grows inside of her.
Who is the protagonist? If not the girl you must decide who it will be.
The information is all there but the order in which you present your logline could be better. Start with the prophetic pregnancy (inciting incident) and go to the outcome of it and the conflict stuff. By the way, who are these supernatural factions?