Mrs. Peeper is the wife of Professor Fred Peeper and mother to their son, Christopher. Her first name remains unspecified. The family, including their dog Ruffles, resides together. At the end of Season 1, Mrs. Peeper announces her pregnancy, though no sibling for Christopher appears or is mentioned in the subsequent season. During Season 2, her nephew Uriah (Uri) Peeper, son of Professor Peeper's brother Kenneth, temporarily joins the household to aid in the search for the missing Ruffles. Mrs. Peeper fulfills a primarily domestic role and is often shown within the family unit, observing Christopher's schemes, such as Ruffles exposing Christopher's fake barbell feat. An inconsistency arises in Season 2 when Uri refers to Ruffles as his own dog, despite Ruffles belonging to Christopher; Mrs. Peeper's specific involvement in Uri's stay or the search is not detailed. The character does not appear in the 2011 Superbook reboot, where the family name is Quantum and Christopher's parents are Professor Crispin Quantum and Phoebe Quantum.