As I'm thinking about this...
This requires a few leaps -
Was Jerry Sandusky manipulative/cunning enough to have chosen a high school to "volunteer" at - complete with a built-in cheerleader (i.e. principal)?
If this young man is related to her, and if Sandusky semi-groomed him with absolutely no intentions of ever accosting him, then it could have served two purposes:
1. A witness who could always say "he did those types of things to me, too, and I was uncomfortable with it but nothing sexual ever came of it" (which is basically what's happening right now - since Frankie P. has taken it to the media).
2. Another witness (in the form of the principal) who would always have his back if push came to shove (as it did with Victim #1's mother).
Also (more stretching here) - if Frankie P. is related to Karen P. then it helps keep her off the hot seat when the tractor beams start shining on her and her famous "he's a great man - better go home and sleep on it" line. Her defense could be "well, he was good to my son/nephew/2nd cousin twice removed, whatever, and there was never any sign of abuse."
It seems pedophiles stalk their victims and enlist the trust of others along the way. Maybe Central Mountain High presented the perfect opportunity for Sandusky at that particular moment in time.