Persistent cold and cough. Is 98 cms.

Dear doctor, my daughter is 2 yrs and 9 months old. She started having cold, cough since mid of  April. It started after we started sending her to day care. After that, on and off she gets cold, running nose and sometimes fever. We are checking with her pediatrician. He said not to worry as she is generally active. Chest is also clear. Once we start medications, she becomes fine. But after an interval, again cold starts and sometime she has temperature too. We observe that she gets cold after she cries a lot since she is generally very fussy and cries a lot for everything. And we also sleep in AC room. Please advise on why this is happening often in an interval of 30-40 days. Also last 2 days, she is having white mucus forming in both eyes. Appetite is normal No vomiting Weight is 15 kgs, height is 98 cms.