The name of this goddess, which comes from the Egyptian Nebet-Het, means “Lady of the House.” It refers to a temple enclosure, rather than a domestic residence. In the Heliopolitan cosmogony, Nephthys is one of the fourth generation of Netjeru (the others being Osiris, Isis, Set, and even Horus in some accounts). As such, She is one of the divinities who facilitate life here on earth, and who contributes to the arts of human civilization.
The fourth generation of gods was somewhat disruptive to the natural order of things at first. There is even a story about Ra, the first Netjer, prohibiting their granddaughter, the sky goddess Nut, from giving birth to these young’uns (despite already being pregnant). Thankfully, the wise god Thoth finds a technicality that allows Nut to have her children while still technically obeying Ra’s decree. So first it was just Ra, and all things were united in them. Then Ra begat Shu and Tefnut, the breath and the waters of life, who are the first male and female. After that, Shu and Tefnut begat another male and female, Nut and Geb, the deities of heaven and earth. While Ra themself is hermaphroditic, the second and third theological generations are dichotomous, falling into a strict gender binary that is strongly tied to the reproductive cycle.
Reproduction becomes a major theme for the fourth generation of Netjeru as well, but in a radically different way. For one thing, there are not just two deities in this generation, but at least four (if not five, depending on whether you choose to include Horus—but more on that in a moment). Only two of these figures—Isis and Osiris—are a fertile heteronormative couple, and they become the darlings of the pantheon for this reason. Set and Nephthys are sterile and barren, incapable of producing any offspring. Set is also attracted to gods of the same sex, and there is reason to think the same might be true of Nephthys. While Isis and Osiris are like celebrities, receiving all the glory and the privilege from their elders, everybody tries to forget about Set and Nephthys in the beginning, pairing Them together and leaving Them to fend for Themselves.