Diana is the youngest daughter of the Poplicola family and sister to Cartilla.

She is a Virgin Huntress of the maiden goddess Diana. Her first appearance is in the fifth book in which she is in love with Aristo. Aristo doesn't love Diana but his friend Lysander does. When she realises that Aristo doesn't love her she cries. Flavia and Nubia come to help her and Diana tells them "... and I wish I were dead!" and Flavia and Nubia both make the sign against evil. Later on Cartilla died of the fever but Diana recovers. Later on in the fifteenth book Diana helps Flavia and Nubia become Virgin Huntresses. Sadly, as soon as Flavia makes an oath not to marry, Flaccus asks if he could marry her. When Flavia declines Flaccus leaves. Later on in the seventeenth book Diana meets Flavia's father and they get married.