I apologize for not taking the time to read all of the responses below and I apologize if this is redundant.
But I've gone through the same with my 3 year old, and a recently released study instantly came to mind:
Honey is a better and safer treatment for children than over-the-counter cough syrup, a new study finds.
"Researchers at Penn State College of Medicine found that a small dose of buckwheat honey given before bedtime provided better relief of nighttime cough and sleep difficulty in children than no treatment or dextromethorphan (DM), a cough suppressant found in many over-the-counter cold medications.
Honey did a better job reducing the severity, frequency and annoyance of nighttime coughing resulting from upper respiratory infection than DM or no treatment. Honey also helped the coughing child and the child’s parents get more sleep."
As long as she doesn't have an allergy to honey, it seems that this could cause no harm to try, but really maybe helpful to your child. I know the next time my daughters symptoms flare up I'm going to try this before heading the pharmacuetical route!