We know that the position of Egyptian goddess Isis at the feet of Osiris could be a matter of sex, a way of positioning herself ready for putting over her husband’s body.
But there is another very important aspect in the dead’s resurrection. We know he becomes a new born, so he needs a mother.
In Ancient Egypt iconography the image of the goddess Nut in the inside of the lid of the coffin was a grant for the mummy’s new life. She, as the mother of Osiris, appears in the surface extended with raised arms and disheveled hair.
We have seen that this was a way of representing the birth of Osiris. In fact, Nut, as the vault of heaven would be bended forwards with her hair falling down. In this position she would give birth Osiris (the deceased).
In the funerary ceremony the mourners with their mourning ritual helped in the dead’s resurrection, if this one was considered a new born, he also would need someone making the role of mother. The mourner in the role of Isis could be this woman who, shaking her hair forwards would reproduce the birth of Osiris (the deceased).
We all know that in a childbirth the baby first shows the crown and the head, while the feet go out in the end. If Isis (the mourner) was symbolically giving birth, the correct position in the funerary ceremony (and also in the iconography) should be at the feet of her newborn son (the dead).
In this case the role of Nephtys would have been helping her daughter’s birth and delivering the baby. That is, her mission was to be the midwife, and for that reason she always appears at the head of the mummy.
Summing up, the scene of the mummy (Osiris) flanked by the two mourners kneeling, Isis at his feet and Nephtys at his head, could be the image of a birth. One woman giving birth (Isis) and being assited by a midwife (Nephtys). Let’s also rememeber that Egyptian women gave birth kneeling.