I've been allows for as long as I can remember I think as long as the kids are old enough to understand that not everything you see in movies is acceptable in the real world then they can watch pg13 movies
What do you think pg13 means? You must be 13 or under parental guidance. So it depends on the parent's assessment of the child's maturity level and whether there needs to be some discussion about reality versus unrealistic portrayals of life in the movie.
Child you about what's PG-13 movie in there at the age of the understand not everything the movies acceptable they're under parental guidance because that is the most important part of the PG-13 movie that you can't do everything in it and that needs to be explained.