Three points indicate that your child's problem isn't herpes. First, nonsexual transmission of genital herpes to children simply doesn't occur, or at least too rarely to be a serious consideration. Second, if your child were infected at age 4, her problem now would have to be a recurrent outbreak. But recurrent outbreaks of genital herpes almost never are bilateral--that is, the sores would have been on one side of her labia or the other, not both sides. Third, recurrent herpes always reappears in pretty much exatly the same, limted area--such as a cluster of blister-like sores in involving the same area of the genitals, buttocks, etc every single time--not with scattered sores, especially around the waistline.
Bottom line: Relax. There is no realistic chance you infected your daughter or that her current problem is due to herpes. If her skin lesions are bothersome (to her, not to you!) then take her to the pediatrician. But this doesn't sound like anything serious.
Good luck-- HHH, MD
Just want you to know you are not alone. I am a mother looking for answers on likelihood of transmission to children as well. It is a terribly scary thing to wonder and worry about. You examine every bump, pimple or scratch with your stomach in a knot praying that this isn't it. Take care.
Please e-mail me at ***@****. I e-mailed you but am not sure it went through. Thanks.