Barbara is Stewie's co-star in an orange juice commercial in "The Peanut Butter Kid".
When Brian convinces Stewie that Peter and Lois no longer have his best interests at heart, resorting to drugging him and putting him through acting "exercises," he decides he wants out of acting. He decides to go on a rampage on the set, tearing open Barbara's top in the process. As a result, he is fired, but Peter and Lois come to realize just how much they have endangered their son.
Barbara is voiced by Rachael MacFarlane.