Numerous children in the world have Cerebral Palsy (CP). It is a disorder that results in impairment or disability due to neurological deficits. Physical therapy has been found to enhance the quality of life for individuals with CP but lacks motivation, which is a crucial factor in rehabilitating CP children. Existing literature shows that Virtual Reality (VR) increases the motivation in CP children. The framework's design is important in developing VR systems for rehabilitating CP children. The available studies have yet to expand the framework part of the VR system. Also, the existing VR systems are not designed according to the needs of the CP children and therapists. This paper contributes a novel framework for developing a VR system for rehabilitating CP children. The proposed framework is to develop a VR system according to the needs of the CP children and therapists that aims to improve the functional mobility of CP children. Future work can include creating a VR system and its validation with CP children through intervention.