In this paper, an interactive multi-agent based system that recognizes child?s emotions and the intensity of emotions to build systems for therapeutic purposes (developed child?s non-verbal communication skills) is presented. It introduces the development of an arousal perception agent that uses a novel emotion intensity estimation model. The arousal perception agent uses cognitive and non-cognitive factors to estimate a child?s intensity of emotions in real time. Flexible and a novel adaptation model based on emotional intensity is developed for the proposed situational control agent. The situational control agent tries to adjust the intensity of negative and positive emotions by changing the status of the game to encourage children to express natural emotions. This situational control agent reacts as therapy (adjusting motivational and encouragement support) for developing children?s emotional expression through affective body gestures. An animated pedagogical agent gives motivational help with instructions (like therapy) as a means of encouragement to naturally express emotions by adapting the system in an interactive manner.