Great story. I think the "magic" line is excellent, as it fits entirely with the way she wants to view the universe.
There could well have been a scientific explanation as to how "you are not allowed science" would work in practice - a combination of GPS tracking, a database, and a lot of computer systems, I would guess - but in the frame of the story it wouldn't have worked, I think. In the novel-length version, or the film adaptation, it would fit, but it would break the flow of the short-story.