Hi again Si-Amun,
KingTutOne.com has a nice article about the God's Wives. Here is a link for you i hope you enjoy.
To answer you question here, Hatshepsut undoubtly was the last God's Wife with any real power for sometime. The office did not die out until the reign of Amenhotep III, where we find reference to an unnamed God's Wife then it apparently was just a title for favored wives of Kings and they don't appear to have used it as the 18th dynasty Queens had. Then nothing really until the 20th Dynasty and Ramesse IV who names his daughter Isis to the post.
After Hatshepsut, her daughter Neferura held the title. After her the title is used by Thutmose III's mother Aset followed by his daughter, Meritamun. During the reign of Amenhotep II his mother Meritra, is given the title. While Tiaa, the mother of Thutmose IV is the last named god’s wife.
While none of these God's Wives acheived any reknown, and certainly none along the lines of the first God's Wife Ahmose-Nefertiti. To conclude that it died out with that last unnamed God's Wife from Amenhotep III's reign would i feel be wrong. With the advent of Queen Tiy, Nefertiti, and Ankhesenamun we see queens with nearly equal positions with their husbands and with atleast the first two real power along the lines of Ahmose-Nefertiti. After the reign of Tutankhamun the office just becomes an occassional title used by the Pharaoh's favored wife.
There is some memory of the God's Wife in the incorperation of Queen Nefertari in the temple of Ramesses II in Nubia and the establishment of her temple own there.
Until the reign of Ramesse IV, and his daughter Isis we really don't have much of a God's Wife existence. He placed his daughter there in the hopes of curtailing the corruption that was rampart in Thebes at this time.
It takes until the 21st Dynasty before we get real reformation of the position and power. The office grows in power, presitage, and offices until the Persians end Egypt's independence.
I hope you check out our article about this most interesting position and office.