As a woman who has spent most of her life dealing with kidney disorder I feel I have some reason to speak on this subject; however, I am not a doctor. Some basic advice I have is wear cotton bottoms, avoid sugar for a little while, drink lots of water, and don't add anything to your bath that is perfumed or a new brand. Furthermore, I drink a lot of Lite (or light depending on brand) cranberry juice; cran is good for you and the Lite variety has the least sugar. Some natural stores have what some people call a "renal tea" which is a mix of different herbs that are good for the urinary tract. For some people with mild infections, or who detect infections very early on, cranberry pills can help. Corn silk tea is a native American remedy which you can find in capsule form now. Some people swear that Oil or Oregano cures all of their infections. This can be found in capsule or liquid form at any natural store or select grocery stores. All of the herbs I mentioned range from 5 to 20 dollars. The Oil or Oregano may be irritating to sensitive skin so you may want to talk to someone who really knows their herbs and anatomy before you try this. I would talk to someone before I used the Oregano Oil since I heard it can irritate sensitive skin such as soars and scars.
I have one GREAT TRICK with juice that will prevent an infection if it is done when you first feel irritation (before the infection has set it). Throughout the day I drink only water and cranberry juice, watch the sugar intake, but the rest of my diet is normal. Shortly before bed I guzzle as much LITE cran juice as I can. I usually start 2 hours or 1.5 hours before I go to bed and guzzle about a cup RIGHT before bed. I usually end up drinking about 32 ounces or so within the 2 hours or 1.5 hours before bed (1 quart, or half a bottle). With a child you will want to use much less juice. The only downside is once i wake up I have to rush to the restroom but I end up feeling just fine. Drink only as much as you can. Drink as much as possible but not so much that you are in pain even more.
I truly hope your health is perfect. Imagine your perfect happy healthy self everyday as much as possible. Good luck.