She struck a deal with Hextia. The witch would provide a way for Cyna to live with the bear (a potion to polymorph Cyna into a bear), in exchange for her first-born conceived with said bear. Unbeknownst to Cyna the potion's effect was only temporary.
Last seen in the wilds outside of Castow.
Last mentioned in Episode 2, when an urchin mentioned Castow's villagers wanted to kill her as punishment for "doing a very bad thing".