16 yr olds dont go to the mikve. If they do we can discuss it then.
There is a special gezeira to make yichud with a penuya tehorah forbiden(Dovid hamelech was gozer). Was there a similar gezera on negiah??
Even if there was, was it on negia with a little girl or with a mature woman(12+)?
I’m not saying there isnt, but is there one?
RH: Why should it be different between an 8 year old and a 16 year old (who went to the mikva)? Are you suggesting that it is okay for anyone to touch the 16 year old girl?