Pamela, I hope you have found something that helps. If not, you may want to see a practitioner who can do muscle testing which will help determine what she is allergic to and what is causing the coughing. You can also look into NAET and BIOSET, which are allergy elimination techniques similar to EFT. They can also eliminate "contaminating emotions".
There is also a electro-dermal testing which is extremely accurate and should be able to tell you the problem with only one test.