PURITY RITES are a nymph ritual meant to strengthen the spiritual connection between lovers. The purity of body (chastity) is the primary virtue, which scholars have rightly pointed out must be overlooked most of the time or there would be no nymph children. It is more often interpret as monogamy. The other virtues are: purity of speech (honesty), purity of spirit (good intentions), purity of heart (love), purity of devotion (commitment), purity of balance (equality), and purity of conviction (courage). Only with all seven virtues can a relationship flourish.
Not sure which part is actual history/myth and which part is her own 'verse, but i loved this idea of the seven virtues.
Also, remember to check her other sites for the rest of this story!