Read all about Epona here: http://www.goddess-guide.com/epona.html, http://www.angelfire.com/journal/ofapoet/epona.html
Epona is often shown with foals or riding a mare.
Epona is linked to Rhiannon in Wales & Macha in Ireland because of their association with Horses. There are several other names in different places as well.
You can read about Rhiannon here: http://www.goddessgift.com/goddess-myths/celtic_goddess_rhiannon.htm
The fairy queen/goddess Rhiannon chose the human Prince Pwyll of Wales as her future husband instead of the husband, of her own kind, that her family had chosen for her.
