There may be… I haven’t met any myself, and I doubt I ever will, but I have no reason to think it’s impossible. I’d have to look at each case individually, unless presented with medical evidence that 100% of humans younger than N years are incapable of giving consent.
Is there a victim? Well, if the child doesn’t feel she has been victimized, she wasn’t subject to any force or fraud, and she (as an individual) hasn’t been found incapable of giving consent, I don’t think she’s a victim.
And I don’t think we can possibly help the child by telling her, “I know you don’t feel like anything is wrong, but what happened was very bad, and your friend is a very bad man who will be going away for a long time,” creating a painful memory from what was otherwise a pleasant (or at least unremarkable) experience.
I disagree. The statement “all children under 16 are incapable of giving consent” makes about as much sense as “all men over 20 are capable of running down the street carrying a television.” Both statements are substitutes for actually discovering the facts of each individual case, and they’re only useful when saving time and money is more important than justice.
I know when I was that age, I acted differently while I was in class than when I was with my friends. Could it be that you’re just not seeing them in situations that demand this kind of maturity?