I read this library book in the 1960s but it could have been published earlier. A young girl is chosen to represent her village by becoming a handmaiden to the temple where the Princess Medea serves. This girl is chosen because she has some special mystical power even though she is very shy. She loves Medea and makes friends with others there. And she tells the story of Jason and the Golden Fleece from her point of view. The book ends with Jason leaving Medea and Medea, in her grief, killing their children. There are many references to the Maiden the Mother and the Crone in the book.
Possibly this is Witch Princess by Dorothy Johnson, published in 1967. It’s told from the point of view of Daphne, handmaiden to Medea.
Yes!! Thank you so much. This is my book and I can’t wait to read it again. A very unusual and memorable telling of this story.