1. Hera is the youngest of Cronus' and Rhea's three daughters. Who are her two sisters?
From Quiz Greek Mythology: Hera and Her Enemies
Answer:
Hestia and Demeter
Hestia is the oldest child of Cronus and Rhea, Titans of Greek mythology. Hestia is the virgin goddess of the family, the hearth, the state and the family home. When Cronus swallowed his children to prevent a prophecy coming true from Gaia about his sons overthrowing him and stealing his power, Hestia was the last to be regurgitated, therefore is considered both the eldest and the youngest of Cronus and Rhea. Later, when Poseidon and Apollo were both trying to become her suitors, a repulsed Hestia begged Zeus to allow her to stay a virgin for life. Zeus accepted and Hestia took her place at the royal hearth.
Demeter is the goddess of wheat, corn and harvest. She is known for the tale of the abduction of her daughter, Persephone. Hades, god of the underworld abducted Persephone to marry her. Demeter intervened and her Hades agreed to share custody of Persephone, for half a year each. This was the explanation in Greek mythology for the yearly change in weather seasons.