My middle child was very good at self filtering what she would read or watch, and still is pretty good. Mostly we just let her self monitor without comment. It did happen more with tv than books, mostly because she watched wayyyy too much tv from 3-5yrs as I was so incapacitated, first by the pregnancy from hell and then the sick newborn who never slept. Anyway, for us, lots of cuddles when wanted and self filtering.