Said actor Rupert Grint about the role: "I was involved with the Lavendar Brown audition and the whole Lavendar thing. Her name's Jessie, and she is really cool, and it's going to be really funny."
Sounds like the 20-year old actress landed a role approximately six million other girls would love to have.
She hasn't had much work, but Cave did appear with Helen Mirren in Inkheart, and will star in a BBC drama called Summerhill next year.
The next Harry Potter installment is set to hit theaters November 21, 2008. Helen McCrory was also recently cast in the flick. She'll play Narcissa Malfoy.