J.C.
Persistent bad breath even with teeth/tongue brushing, gargling, rinsing, etc comes from the intestinal track. Does she have regular bowel movements? I have also noticed my kids will get persistent bad breath when they have a sinus infection. My only suggestion is a chiropractor as they are the only ones that can get to the bottom of it without a 1,001 tests. Tehy can ususally give you some really easy home remedies or massage techniques that will help the intestines. A regular doctor probably wouldn't because it's not a disease & probably isn't causing any other noticable problems. Hope this helps!