Eurydice was not mentioned until Persephone the Daring. She is a mortal pop star, and she sings with Orpheus and has a romantic relationship with him. She is not a student at MOA.
In the story
She has a sleepover with Persephone, and she took Adonis out, since it was Persephone's turn to watch Adonis. They went to the Underworld and found her in a snake field, and she nearly got killed by one. She also had a mini concert in the forest with Orpheus, and she dared Iris to make a rainbow in the shape of a heart, and dared Medusa to use her snakes, but Medusa refused.
Eurydice is known for having a lot of fans. She is also very risky and daring. When Persephone was holding on to Eurydice's hand, she let go and fell.
Eurydice has pink hair tied in a pony tail, and she where a lot of pink bracelets on her hands. She wears a pink chiton. She wears mismatched earings and sandals, something that Persephone claims is very daring and impresses her.