Sithathor Iunit was the daughter of the 12th Dynasty king Sesostris II. The name of this princess's mother is unknown. She was the sister or halfsister of Sesostris III and the aunt of Amenemhat III.

It is not known to whom she was married and if she had any children.

She was buried in a tomb near her father's pyramid at Illahun. Although the tomb was almost completely plundered, five wooden boxes, two made of inlaid ebony, were found in a hidden recess. These contained the princesses' necklaces, bracelets, diadems, anklets, rings, a cosmetic container and a lovely silver mirror with an ebony handle.
   

A pectoral necklace shaped around the name of her nephew Amenemhat III was found in Sithathor Iunit's tomb.

One of the necklaces was shaped around a cartouche with the throne name of Amenemhat III, an indication that she at least lived until the long reign of this king.
 

A gold diadem with uraeus (left and centre), wig ornaments (centre) and a silver mirror with an ebony and gold handle (right) are just some of the many lovely items that were found in the tomb of Sithathor Iunit.