Cloven hooves - Megan Lindholm

Evelyn is a solitary child, preferring to wander in
the woods in all weathers rather than socialise. Her secret is a fantastic companion: a faun with whom she plays in the woods.
Years later Evelyn finds happiness as a wife and mother, but life turns sour when the family move to Tacoma where her husband is asked to fill in at his
father's business.
Evelyn's husband's wish for them to stay permanently with his family causes a rift between them and then a terrible tragedy makes the situation even more impossible.

Miraculously, when she needs a friend, Evelyn's childhood companion reappears in Tacoma.
Pan, now an adult satyr and a secret friend to both her and her son, eventually becomes her lover.
He leads Evelyn on a odyssey out of her failed marriage to fulfilment in the woods of Alaska.