Who is Joelle Van Dyne from Infinite Jest: A Novel and what is their importance?

Joelle Van Dyne is an actress who appears in the Entertainment. In the video, she reaches down to the camera as if talking to a baby, and apologizes greatly. She is also the ex of Orin Incandenza. She is known as 'The Prettiest Girl of All Time,' but wears a veil because those who see her face will fall in love with her. It is later reveals she had been disfigured by an acid attack. She ends up in the Ennet House Drug and Alcohol Recovery House because she tried to overdose on cocaine as a suicide attempt.