In the Ennead of Heliopolis, Nephthys was the daughter of Geb and Nut and the sister of Osiris, Isis and Seth. In many texts she is regarded as the wife of the latter. One tradition calls her the mother of Anubis, with his father being Osiris. Other sources say that Re was the father of her child Anubis-Sopdu. Nephthys's functions are not entirely clear. Not much is known about a cult centre or temple, although the names of a few priests of Nephthys have survived. She was usually worshipped alongside another god, for example Seth in the New Kingdom and Antaios in the Late Period. In addition to a lack of data about a definite cult of her own, Nephthys's name, which means 'Lady of the House', does not give much information about her function either. She usually appears as the companion of her sister Isis, but she herself remains rather colourless. Her appearance is possibly due to the Egyptian need for pairs, which can also be seen with other goddesses, such as Tefnut and the female gods in the Ogdoad of Hermopolis. Together with Isis, Nephthys often appears as a mourning female beside the deceased, sometimes in human form but also as a bird. The goddesses are also often depicted together in the scene of the weighing of the heart in the Book of the Dead. She also functioned as a protectress of one of the Four Sons of Horus, Hepi, to whom the lungs of the deceased were entrusted. In the Late Period Nephthys was associated with Anuqet and worshipped with her in southern Egypt.