Any human sample will work regardless of the sub donors age. Just make sure the sub donor is not overhydrated or not taking medications. Scooping the sample out of the bowl water is a bad idea. Depending on the bowl water/urine ratio, the creatinine and sg level can drop low enough for the lab to rule the sample 'not consistent with human urine".

I see no problem in harvesting a urine sample from a child to pass a drug test. If I had to do it all over again and still have living parents facing a drug test, I would gladly give my clean urine sample for them to pass the drug test. Whatever it takes to keep food on the family table, clothes on our backs, and a roof over our heads.