I'm not sure Athena was originally a Proto-Indo-European Goddess. Hellenic religion is heavily syncreticized with other cultures and has a lot in common with Near Eastern religion.
That's entirely possible (that she's not originally PIE) and is Near Eastern. Of course, how many permutations of a god or goddess can one have before there's an overlap? Saraswati is unquestionably Indic/Vedic because she is the personification of the Saraswati River. It was thought to be mythical until satellite images showed a dried river bed where the river was said to once flow. Tangentially, this may also go to the collapse of the Indus Valley Civilization. A drying climate may have forced the inhabitants of the IVC further east to the Gangetic Plains area, which was still quite wet and fertile. Sorry, Mr. Tsoukolos... no alien nuclear holocaust at the IVC.