Green mucous is usually infective. Post viral it can be due to sinusitis and sometimes the pent up mucous shows changes in color. Stat giving steam to your child twice a day so that the secretions start coming out. You can use saline nasal spray which will help her symptomatically also. A complete physical examination will be required to give a proper diagnosis and for treatment.

Green mucus is indicative of infection - can be viral or bacterial. If persistent then sinusitis has to be ruled out. Kindly consult for further discussion

Green mucous is considered as infectious kindly consult for further management