Let me just say first that even though a lot of people like this movie, it's kind of stupid and boring. Your kids probably won't want to watch this, but if they do, as long as they're older than 12 it should be ok for them because it really isn't that bad.
I love this movie, actually I love all three. "Meet the Fockers", and "Little Fockers" are favorites as well. This movie is hilarious from start to finish. I give it a 12+ because compared to the movies made in the past few years that have received PG-13 ratings, this film is honestly harmless. There is some language and sexual content, but nothing a 12 year old hasn't heard before. Overall, great movie, see it if you haven't!!