The Since U Been Gone star reluctantly made the film with fellow American Idol finalist Justin Guarini shortly after she won the first season the TV talent show over a decade ago and she recently discovered the woman she hired to help look after her 11-month-old fan is a huge fan.

Clarkson tells Rolling Stone magazine, "She was like, 'My roommate and I used to watch it all the time! I'm totally going to show your daughter From Justin to Kelly'. I'm like, 'I will fire you'."