Who is The Ravished, Persephone from The Girl Who Circumnavigated Fairyland in a Ship of Her Own Making and what is their importance?

Early in the narrative, and several times throughout, September is referred to as being one of "The Ravished". It's not until the second last chapter that the narrative (in the words of The Green Wind) actually explains what that means (September, it's interesting to note, never actually asks). The Ravished, according to the Green Wind, are like the demi-goddess Persephone, daughter of the earth mother/goddess Demeter. One spring day, Persephone was kidnapped by Hades, the God of the Underworld, and taken with him to live in his kingdom beneath the surface of the earth. Demeter searched and searched for her daughter, grieving and angry and abandoning the crops and fields, which eventually withered and died. Eventually, she discovered Persephone's whereabouts, and was told by an oracle (prophet) that if Persephone had not eaten anything while she was in the underworld, she could return home - but if she HAD eaten, she would be doomed to stay there forever. When Demeter finally found her daughter, she was dismayed and angered to learn that Persephone had eaten six pomegranate seeds. As a result, Persephone remained in the underworld for half a year (fall and winter), and in the world of the living for the other half (spring and summer). Because she ate while in Fairyland, September is allowed to return there half the year, but must stay in the human world for the other half. An important question, however, is this - since September hasn't actually eaten any fairy food when she is identified by The Green Wind and Betsy Basilstalk as one of the "Ravished", technically she isn't one. So how do they know?