One god under two names, across The Cradle of Cities.
Ninlilnin-lilLady of the Open Field — wife of EnlilThe Cradle of CitiesMullissumul-lis-suQueen of the Assyrian Pantheon — Consort of AshurThe Cradle of Cities
Why the sources call them one god
Her Akkadian counterpart is Mullissu (which becomes the title "Mylitta" in Herodotus)