Urine doesn't contain DNA. That was what the argument was. Most people consider it unusual for a 7 year old to have a discharge in the vaginal area.
Now I understand where ya'll are coming from... thank you for your polite and informed replies.
I have an idea about this..but let me look something up first.
Urine doesn't contain DNA. (sure about that ?)
Even if true, the crotch of a pair of dirty underwear WILL CONTAIN DNA ! Urine stains or not !