 Mr. Digby has been appointed Faculty Advisor for the school s milk fund drive and has arranged for Pritchart s dairy to donate 200 pints of milk a day for the school. However, there is one condition. Pritchart wants to photograph the typical American farm family and use it in his advertising. Doris goes along with this but Mitchell who is in charge of the shoot wants the boys to have sisters. When the boys bring home school friends to pose as their sisters it s not quite the photo Pritchart had in mind.