Celtic women used to fight alongside the men, were equal to men in fighting, went on raids with them, and were just as likely to abduct women as the celtic men were.
Red Sonja shouldn't be waify or look like a typical catwalk or bikini model, but should look really solid and strong. She should have arms that look able to swing swords and grapple and wrestle, a powerful core instead of a wasp waist, and strong legs from running around the hyborean wilderness all the time.
More Red Sonja:RedSonja vs. Dire WolvesRed Sonja with Severed Pict Head