She says "fell from the sky one night like a shooting star" (hence me thinking: aight, that's meteoric iron), but now that I read it again, it fell already forged in a single piece with a thunderclap, in the hour of greatest need, yadda yadda yadda. It could be just aggrandizement, made by the ignorant common folk or the not so ignorant landholders trying to attach some divine right to rule through legend and symbolism.
But no, seeing what kind of world we are dealing with, it was most likely the sword of a schmuck from a world that discovered steel and it fell through a portal after a lubrication accident.