Continous cought at night. Some test?

Hello Doctor My daughter is 5 years and 10 months old ,weighs 21 kg . She was preterm baby ,birth weight 900 grams . Now she is perfectly a healthy child. Past one month she had cold and cough .cold is  settled , but coughing is there. She is active and no coughing during daytime . coughing and vomiting only at night while sleeping . night cough is there for nearly 20 days . Light snoring sound is heared while she sleeps.light cold is also there when she is active . Earlier when was 3 years she had wheezing during cold season but she recovered soon.after tat no complaints. I went to paedtrician twice but not cured.paedtrician said it is bronchitis. Next wat should I do ? Should I take to paedtrician and take some test ?? I have attached the prescription. Pls help.