Cora: Rise of the Fallen Goddess by A.L. Hawke

Cora is the goddess Persephone living in ancient Greece. To shelter Cora from prophecy, her mother, Demeter, sends her away. The young girl is raised by the nymph Nephrea. But prophecy portends danger for Cora. After her fall, Demeter threatens to freeze the world. Nephrea offers a sacrifice, but it might be more than the goddess who needs saving.