Who is Lady Mi and why is she an important Egyptian royal? Is it only women who are depicted as be human and aging?
According to the inscription, Lady Mi was not royalty herself, but likely lived in the palace and was instrumental in elite rituals.
Rather than a gendered difference, I believe, this was more of a shift from dynasty to dynasty, ruler to ruler. There are also depictions of male rulers and elites as "mature individuals," depending on the era. This stautette, dates to the same time at the nearby wooden statue of Amunhotep III who is also depicted as aging.
Oh, I was not aware of any acknowledgement of human aging in Egyptian art before tonight!