” surprisingly indicated that it was woven from the hair of a woman, who researchers believe made the object herself.”
Based on what? What factual evidence leads to that belief?
It isn’t a belief in the first place. Surviving early writers about the practice noted that men and women were employed making khipu. The linked study notes that khipu are sometimes found among grave goods, and one grave previously thought to be a male burial turned out to be a female burial. Human hair was used as a sort of signature in khipu, not apparently as the primary source of the medium. The one under study was entirely human hair rather than the usual llama or alpaca material.