It's a female, not a male.
The people who were affected have moved on from the issue and do not wish to dredge it up and getting the guy convicted will indeed dredge it. If she does anything to this guy, it will almost certainly make life tough for those she's apparently attempting to "help" out.
Also, this person is so amoral that it may be necessary to err, expire him, if you're going to bring violence upon him.
.. And he may not be a paedophile - at 18 years old, he may have simply perceived no way to get laid and basically amorally used that which was around him, to satisfy himself.
He certainly deserves something, but I'm wondering what it could be with the parameters involved.