Known as the Lady of the open field or the Lady of the Wind, Ninlil is described in Sumerian Religion as the consort goddess of Enlil, associated with earth, wind, and storms. Although there are various versions about her parentage, she is commonly known as the daughter of Ninshebargunu or Nibada, an ancient goddess of agricultural deity and Haia, the god of the stores. While according to Akkadian sources, Ninlil was the daughter of Antu and Anu, the divine personification of the sky, in other versions, she was the daughter of Anu and his mother Nammu, the goddess of sea.

Although Ninlil was a powerful goddess, it is the relationship with Enlil, her husband that forms a major component in the social identification and status of the goddess. The mythical story of Enlil and Ninlil is a tale of coming of age, whereby a Maiden goddess and a god grow from unsure adolescents to assertive adults in love and committed to a future together.

The mythical story of the rape of Ninlil by her consort, the wind god Enlil, reflects the life cycle of grain. It started when Enlil saw Ninlil bathing in a lake and was sexually attracted to her. Consequently, the pair had sex, without having any experience in affairs of the mind, body, heart, and soul, as Enlil forces himself onto the maiden and impregnated her.

However, although she carried the seed of the most coveted of the young gods, Ninlil felt insulted for the forceful rape and took Enlil to the assembled Anunnaki gods, demanding the punishment of her rapist. Enlil was found guilty and was condemned to the underworld kingdom of Ereshkigal. However, although Ninlil did want Enlil to be punished, and Enlil did not try to evade punishment, Ninlil decided to follow him to the Underworld and sets out immediately to descend, intending to rescue her stubborn lover back to the world above.

In the Underworld, Enlil met Ninlil thrice in three different disguises, and begged for her love, without divulging his true identity, and as his hardest judge, she reasserted herself as a true goddess to oblige him. Enlil met and impregnated her thrice in the disguise of the gatekeeper, as the man of the river of the nether world and as the man of the boat, and consequently, she gave birth to Nergal, the god of death, the underworld god Ninazu and Enbilulu, the god of rivers and canals. It seems that she knowingly received in her womb three more seeds of Enlil, and received them into herself to heal and rescue the god, and in the end, both them came back from the Underworld, to form one of the most loving couples in Mesopotamian myth and Religion.

Ninlil was explicitly identified with the grain goddess Ashnan in Mesopotamia, and the goddess of birth. She gave birth to the moon god, Sin, and daughter of Haia, god of the store, and Ninshebargunu, the goddess of agriculture.

It is considered that she might be a form of the Mother Goddess as she was often called the mother or merciful mother, and as a benevolent and merciful goddess, she intercedes with Enlil on behalf of the mortals. Particularly, during the time of the Third Dynasty of Ur, many votive offerings were brought to her and since the Old Sumerian period, she was known in Nippur and Shuruppak as the wife of Enlil. Even, during the Old Babylonian period, several hymns were written in which the suitor prayed Ninlil to influence Enlil.