Vivian is talking to Rory on his cellphone while Serena is playing her song.
Vivian is later seen at the school talent show, sitting next to Benny's Grandma, talking her ear off about how excited she is to see Rory play with Ethan and Benny's band, Muse-o-tronics. During the performance she shouts "Pop and lock, Honey!"
She is affected by Serena's song and tries to attack a fellow audience member.
According to Rory she doesn't know that Rory is a vampire, and if she did, she would ground him for a month.