Based on the experimental data we propose a statistical model for description of stimulated fluorescence effect (lasing) of the ensemble of polydisperse micron droplets containing a laser dye. Various statistical criteria for identification of the stimulated fluorescence effect are considered in the frameworks of the model. The experimentally obtained statistical characteristics of the fluorescence of the rhodamine 6G solution in ethanol suspended into droplets of different size by the laser pulses of 0.53 μm wavelength are presented in the paper.