Erin Chambers is Rita Barksdale's daughter, who was raised to be a trophy wife. Based on information in the episode "I Don't," it appears she is 21 years old and her maiden name was Chambers. She is the only cousin of Daria and Quinn Morgendorffer on their mother's side of the family. Daria has a low opinion of Erin.

In "Aunt Nauseum," it is revealed that Erin married Brian Chambers because he gave her herpes and she thought no one else would want her. In this episode, Erin wants a divorce but is eventually talked out of it by Brian and her grandmother, leading to a second honeymoon for the two.