Maia

Maia (Ancient Greek: Μαῖα) was the eldest of the Pleiades, the seven daughters of Atlas and Pleione. Her sisters and her were born on Mount Cyllene in Arcadia and are sometimes called the mountain goddesses. She was a lover of Zeus and the mother of Hermes.

History
Maia and her sisters were pursued by Orion and turned into doves to preserve their own safety.

Zeus, in the dead of night, secretly begot Hermes upon Maia, who avoided the company of the gods, in a cave of Cyllene. After giving birth to the baby, Maia wrapped him in blankets and went to sleep. The rapidly-maturing infant Hermes crawled away to Thessaly, where by nightfall of his first day he stole some of his half-brother Apollo's sacred cattle and invented the lyre. Maia refused to believe Apollo when he claimed Hermes was the thief but Zeus then sided with Apollo. Finally, Apollo, enchanted by the newly invented lyre, exchanged the cattle for the instrument. Maia also raised the infant Arcas to protect him from Hera, who had turned his mother, Callisto, into a bear.

Maia is the activation word that used to make the flying shoes of Hermes sprout wings and fly; inspired by his mother's name.

Appearance
Maia was the oldest, most beautiful, and the shyest of her sisters. She was sometimes called "Mountain Maia of the lovely black eyes".

The Lightning Thief
Maia does not appear in the series, but the winged tennis shoes her son Hermes gives to his children sprout wings and fly whenever her name is spoken, showing that Hermes thinks of her often.

Trivia

 * Maia is a star in the constellation Taurus. Named after this female deity, it is the fourth-largest star in the Pleiades star cluster.
 * She is the only deity except for Apollo who's Roman counterpart is of the same name as of the Greek.
 * Some scholars think that the month May is named after her.