Shepenupet II was adopted by her predecessor in office, Amenirdis I, a sister of Piye.

Shepenupet was God's Wife of Amun from the beginning of Taharqa's reign until Year 9 of Pharaoh Psamtik I.

While in office she had to come to a power sharing arrangement with the mayor of Thebes, Mentuemhat.

[3] Shepenupet was compelled to adopt Nitocris, daughter of pharaoh Psamtik I, who reunited Egypt after the Assyrian conquest.

In 656 BC, in Year 9 of the reign of Psamtik I, she received Nitocris at Thebes.