I think it is just fine for kids. The humor is very vanilla. In fact I was there when I was about 10. I don't think I was harmed by the experience. In fact I didn't really get it. I enjoy it much more now that I'm older.
Early inthe night , it's OK. Later it gets a little "risque"...not pornographic, but certainly there are a lot of "double entendres". The shows in the library can be a little risque too.
Last trip, we were at the last show of the evening, which is like 1AM. There was a family there, with a little girl who looked baout 6-7 years old. The performers made a point of saying "Oh there's a young child here at this show which may feature some adult humor" thnking that the parents would leave with the kid, but they didn't.