Hi Sachin, Thanks for writing your query. Piriton CS is a cough syrup helpful in allergic dry cough. It contains Dextromethorphan and Chlorphenriamine. Dextromethorphan is used as cough suppressant. Chlorphenriamine is an antiallergy medicine. This syrup will be helpful if she is having allergic dry cough. If her cough is due to increased mucus secretion or due to bronchoconstriction, this syrup will not be very effective. Then she will need a cough syrup containing bronchodilators and mucolytics. My advice to you would be to get her examined and auscultated by a Paeditrician and start treatment accordingly. Take care of her enviornment. It should not be cool and she should be properly clothed. I hope this is helpful to you. Thanks.