Hi Amy,
Did your doctor prescribe sinus rinses for your daughter? Our clinic has protocol for sinus rinses that include antibiotics. For example, if you culture MRSA, you add Bactroban to the sinus rinse. If you culture Pseudo, you add TOBI to the rinse. My daughter was having significant sinus involvement, but adding sinus rinses (just the plain ones)changed her sinuses tremendously.
My daughter also cultures a fungus and we also feel that the fungus causes sinus issues. Treating the fungus, may also give your daughter some relief from the sinus issues.
Just some suggestions...best of luck to you!!!