Gaea is a primal goddess, personifying the Earth itself, and was born of the nothingness of the universe, along with Chaos and, in some versions, Eros.
Consorts & Children:
By Chaos, she bore Uranus ("sky") and Oceanus ("ocean"), and it was through Uranus that she gave birth to the Cyclopes, the Furies, the Giants, and the Titans. Among the twelve Titans were Rhea and her brother Cronus, who, with help from Gaea, overthrew Uranus as supreme deity. However, when Cronus began swallowing his and Rhea's children out of fear that they would in turn overthrow him, Gaea helped the youngest, Zeus, overthrow Cronus. After Zeus had banished the Giants to the Underworld, though, Gaea conceived the fearsome Giant Typon with Tartarus out of revenge.
Being a personification of the Earth itself, her sacred symbols are the dirt, trees, flowers, stones and rocks, and animals that inhabit it.
Gaea Around the World:
Her Roman equivalent is Terra, though she's also been identified with the Greek Rhea, the Egyptian Geb, the Celtic Anu/Danu, and the Celtic Dôn.
SOURCES: Greek Mythology.com, Encyclopedia Mythica, & Wikipedia