Harper, best known for "Rhoda" and "The Mary Tyler Moore Show," will appear in the second new episode of 2011, according to TVGuide.com. The actress will portray the sister of Lesley Ann Warren in the episode. Warren guest stars as the mother to Terri Hatcher's character, Susan Delfino.
Harper has also appeared on Broadway in The Tale of the Allergist's Wife, Ovid's Metamorphoses, Paul Sills' Story Theatre, Something Different, Subways Are for Sleeping, Wildcat and Take Me Along.
"Desperate Housewives" airs Sunday evenings at 9 PM ET on ABC Television. Check local listings.