So your point is that you are upset nothing was done until it became illegal?
Kids should not be having sex together, but until one of them becomes an adult (and even then there has to be more than a three year age differential in most states) then there is little that can be done realistically.
Nor do we know if authorities were even aware before.
Parents should tan their hides. If the kid is old enough for sex, they can move out and support themselves!