A visit from a parent who is not into the hobby has prompted us to look into this issue, and while we always assumed that being a licensed establishment children would not be allowed, it turns out the host venue are ok with the idea... as long as the parent is present throughout, the children are respectful and well behaved, and they do not go to the bar.
Now obviously with us not starting till 7pm and going on quite late the chances are that on school nights we won't be the best venue for kids anyway. However, during the holidays, this may be less of an issue. Of course it's the parents choice at the end of the day, but as far as the club is concerned, they are welcome.
Obviously, it is an adult environment, I won't be expecting club members to watch their language or their jokes, if the parent (who must be present throughout) thinks we are an unsavoury bunch then they do not have to let their child come, that is their decision not ours. But if we are as welcoming to a young gamer as we would be to any other gamer, then I can't see it being a problem.
Ron, this may of course be of interest to you. The other dads in the group have far younger children though of course the invite is open to everyone.