Geillis Druid Ritual

Claire goes in search for Geillis and finds her in the woods doing a druid/pagan ritual. Claire notices the similarities to the dancers at the stones. Claire watches on as Geillis dances noticing Geillis is pregnant. When Geillis finish’s her ritual she calls for Claire to come out. Claire confronts Geillis about the pregnancy. Geillis tells Claire not even Arthur knows and when Claire asks how that is possible Geillis tells her Arthur hasn’t seen her out of her cloths. Geillis confesses that Dougal is her love and the child is his. Geillis tells Claire her ritual or summoning is to ask for Dougal and her freedom from their respective marriages.

What is the connection to the dancing similar to that of the stone dancers?

Source: By the Pricking of My Thumbs