9 year old daughter had pain while urinating after swim practice particularly after doing the breast stroke. Anything to prevent that?

Check Urine First. Your 9 yr old daughter had painful urination "after swim practice". Painful urination is a hallmark sign of a bladder infection and should be addressed before other causes are entertained. From here, irritations in the genital area can be caused by soaps, chafing, & chemicals (ex. pool water). Your daughter should see her doctor to check for infection and irritation in order to address prevention.