You know the stereotypes.
5000 years ago, a horde of milk-drinking, pot-smoking, trouser-wearing, pastoralist warriors rode (on horses) out of the Pontic-Caspian steppes to take over much of Eurasia. We can follow the trajectory of their expansion by the kurgans—burial mounds—that they left behind, in which those very warriors were buried with full panoply of arms.
There's a certain amount of truth to the stereotypes, certainly. But with the advent of genetic science, a fascinating new window of insight into the ancient Indo-Europeans opens up for us.
In fact, one in twenty-five of those warriors buried with arms in those barrows was a woman (Winegard 99). One in twenty-five.
Take that, Marija Gimbutas.
Really, we shouldn't be surprised. We know that women in historic Celtic-speaking societies underwent arms training. (Think of Boudicca. Being able to defend yourself is a valuable skill.) Well into historic times, the Scythians—essentially, Indo-Europeans who stayed on the steppes—were known for their women-under-arms, who gave rise to Classical legends of the Amazons. Achaemenid king Cyrus the Great, unifier of Persia, lost his head (literally) after treacherously attempting to annex the kingdom of Scythian warrior-queen Tomyris of the Massagetae. (He had previously proposed marriage to her, but she turned him down.)
Warrior goddesses turn up all across Indo-Europeandom, from the Morrigan in the West, to Durga in the East, with Athene in-between. Why would we be surprised to find an underlying social reality to match? Religion reflects society, as every student of either knows.