What Causes Redness In The Opening Of Urethra?

Is the opening of the female urethra suppose to be red? My 9 year old daughter is experiencing pain in the opening and the tissue is red; sometimes the outer area has red streaks. Over the last year I have taken her to the doctor several times and they have ruled out bladder infection and yeast infection. They prescribed a tube of Nystatin, but it only clears up the outside area.