From the recording The Ancient Egyptian Lyre
According to ancient Egyptian mythology, Nephthys is a goddess of the dead who, like her granddaughter Qebhet, provides assistance to the souls of the deceased. She was so helpful to those in the afterlife that one of her titles was "Friend of the Dead" and she was also thought to bring news of the deceased back to their relatives on earth and comfort them in their time of mourning.
Her symbols are the hawk and the temple and the sycamore tree, one of the more popular trees depicted in inscriptions from the Egyptian Book of the Dead. She is the mother of the death god Anubis and was associated with the setting sun, twilight, and darkness. Prayers were offered to Nephthys at twilight for protection and also to aid her as she struggled with her husband Set to defend the Boat of Ra (the sun god) from the serprent Apophis as it made its journey through the realms of night.
Once she became associated with the afterlife and the care of the dead the linen which was used to mummify the deceased was known as "tresses of Nephthys" and it was thought that she, along with Selket, helped to breathe life back into the soul and help them on their eternal journey. Nephthys came to represent the promise of a helper at one's side in the afterlife who would look after and protect the soul and who assured the living that death was nothing to be feared. The realm of the afterlife was only a new land one traveled to and old friends, like Nephthys, would be waiting to offer their protection and guidance in death as they had throughout life.