My girlfriend is in her twenties. It's very cold recently. She coughs at night.
Cough is actually a self-protection function of the human body. Usually drink warm water, and it will be fine in a few days. Artificial cough is not necessarily a good thing, but if you cough too much, you must be treated if you have asthma symptoms.
From your description, it is not a big problem to cough less during the day and more at night. Tell your girlfriend more and don't have too much psychological pressure. It's just a minor illness like lung flu, but taking too much medicine is harmful to your health.
I wish my girlfriend a speedy recovery!
After reading the supplement, I stopped using compound methoxyphenamine capsules, which was not symptomatic. Go and buy her some cough syrup. Just drink it when you cough. Actually, it's a very simple thing. Don't bother, do you think?