Mrs Riley was a wealthy woman who lived in the city administered by Governor Breck. She was the owner of the chimp Lisa, whom she sent on an errand to fetch a book while she visited a hair salon (it was there that Lisa first met her future husband Caesar). Mrs Riley then went on a lunch date with "her beau".
Mrs Riley seemed quite high-ranking among City Society, and was later seen at an ape auction attended by Breck, where she chatted with a successful businessman. At this auction, Caesar was bought by Breck and shortly afterwards was assigned to work in the Ape Management control center, where he also found Lisa working - however she was later bringing another book for Mrs Riley when she showed her rebelious sympathies by throwing it to the ground.
- Mrs Riley's husband is mentioned in the film's novelization as Leland Riley. He isn't in any scenes, but it's his stroke that allows Mrs Riley to meet her "beau".