She is not a deity from the Eleventh Dynasty, is not known as the Goddess of the Waters, and has nothing to do with dolphins or the flooding of the Nile.
In fact NETERAANTMWMW is a modern invention, a charming but utterly fictitious Egyptian goddess created as a hoax to fool mythology websites. For more information, please consult her non-existent inscription on the tomb of Nefertiti.
Those of a philosophical disposition may wonder what difference there is between a genuine non-existent being and a fictional one. We include her in our Holy Database for completeness, and because we suspect she might be the consort of the FLYING-SPAGHETTI-MONSTER.
Meanwhile, if you wish to believe in NETERAANTMWMW, please feel free. She would probably appreciate the attention.