Brief Answer:
It could be atypical bacterial infection/allergic/recurrent viral infection

Detailed Answer:
Hello

Thanks for the query

In the present situation where there is history of repeated cough,cold,sore throat I would like to know
1)Is every episode is associated with fever or only the initial one was?
2)Is there any past history of wheezing/nebulisation?
3)Is there any family history of allergy?

As already been tested for strep,the streptococcal sore throat has been ruled out.
The most common cause of cough/cold,sore throat in this age is viral infection.
The possibilities in your case could be
1)An initial viral infection and cough,cold and tonsillar involvement is persisting
2)An initial viral infection precipitating the allergic component and the symptoms are persisting
2)Recurrent viral infection
3)Infection by an atypical bacteria like Mycoplasma pneumoniae(common in this age with these symptoms)
4)Persistent/nonresolving tonsillar or sinus infection

First I would like to get her evaluated by pediatrician to see tonsillar enlargement or involvement of sinuses by proper clinical examination.
In case of positive family history and/or past history suggestive of allergic disorder I would like to get a blood test done for eosinophil count and serum IgE levels.
I would like to give azitromycin(for atypical bacteria) and antiallergic (montelukast with cetrizine,as this will take care of allergic component).Both of these are prescription medicines,so you have to get it prescribed by a physician.Along with this I will avoid cold eatables and will give steam inhalation and warm saline gargle every time when she gets symptomatic.
I hope this answers your query.
I shall be happy to answer if you have any further query
Regards

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