Who is Aglaya Ivanovna Yepanchin from The Idiot and what is their importance?

Aglaya is the youngest and most beautiful of the Yephanchin daughters. Her father and mother have great plans for her, intending Aglaya to marry the perfect man. However, Aglaya shares her mother's eccentricity and stubbornness and wants to do as she pleases. Unfortunately, these characteristics mix with great immaturity. For example, she is deeply in love with Prince Myshkin, yet often treats him badly, calling him an idiot and saying she will never marry him. The characters all blame the Prince for losing Aglaya, but it is because of her inability to grasp the complexity of situation that the Prince goes off with Anatasia Filippovna.