System and methods of controlling fluid diversion during stimulation treatments are provided. Real-time measurements are obtained from a plurality of fiber-optic data sources at a well site during a stimulation treatment being performed along a portion of a wellbore within a subsurface formation. Fracture growth and stress within the subsurface formation surrounding the portion of the wellbore are determined as the stimulation treatment is performed, based on the real-time measurements and a fully-coupled diversion model. An amount of diverter for a diversion phase of the stimulation treatment to be performed along the portion of the wellbore is determined, based on the fracture growth and the stress within the subsurface formation. The diversion phase of the stimulation treatment is performed by injecting the amount of diverter into the subsurface formation via at least one injection point located along the portion of the wellbore.