Quite possibly - unfortunately. In an incident in my town involving a teacher and a 15 year old girl, he got no jail time at all - just 10 years probation (deferred adjudication) If he does not violate probation, not only will he have no jail time, his record will be cleared. Men teachers get away with it, too.
Of course, comparing these two cases is anecdotal. After all, Mary Kaye Letourneau did hard time. I would be interested to see a comparison of average terms for similar crimes, though.
Only after she ignored the judges orders and continued "dating" the young man in a parked car.