Hello, The viral infection has most likely set off airway inflammation that can persist in some children as asthma. Cough usually night-time cough is a sign of asthma in children. Asthma can also be allergic and house dust mite allergy is the commonest of the triggers. It would be unusual to develop at this age, but not so, if your child has atopic eczema, food allergies as well. So please ensure she is checked out for both allergies with a specific IgE test screened by Phadiatop panel, and treated for presumed asthma. Best Wishes.