Sounds like GERD to me, is it the valve in her throat or her lower esophagal sphincter which isn't closing properly?
Has she tried PPI's? They never worked for me very well either. If they are helping it is minimal.
A naturopathic type person told me to chew on digestive enzymes such as papaya, and licorice extract, and acidopholus - natural substances which aid in digestion. I never know who to believe - those who are keen on speeding up digestion with these substances, or those who want to suppress acid production which in turn would only slow digestion.