In the Ulster Cycle sagas, Emer, the wife of the great hero Cuchulain, is his greatest strength. She rules her own household, often advising her husband. Emer supports Cuchulain even as he strays into the world of the Sidhe with Emer's ethereal rival, Fand. Emer knows her husband will always return to her side. Even past his death she refuses to leave him, climbing into his grave, sharing her strength with his as he passes into the Other World.
Secret societies are still a reality as well as being portrayed in myth and legend.
There being no Celtic literature from the Roman period we are forced to rely on the narratives of the invaders of Gaul and Britain. These women were possessed of amazing powers, able to beckon the wind and sea to do their bidding, shape shift into any animal, cure serious illnesses and know the future. The last theme that I will discuss is the idea that the hero must come to the realization of his or her full potential by their own means and not by those boons given to them by the gods or by magic. I call the 'true' initiation. For example there is the story of Llew Skilful Hand, the son of Arianrod.