I totally agree, children who don't behave well are a major distraction at meetings.
My kids are 10 & 12, they've attended 2-5 meetings every week with me for the last three years. They know it's important to be quiet and respect that, if they're loud I can get their attention very quickly and quiet them down. I make sure they have drinks and snacks and something to keep them occupied quietly, a book or activity.
Like kj3880, I'm like the freakin' Pied Piper of AA. For some reason (and I hate to say it but it's mostly the single mothers) people feel like they can leave their unruly children at my table so our kids can play together. If they don't respect my request to be quiet, I simply ask them to leave the table and later on I can set the boundary with the parent. I'm there for my recovery, not to be a babysitter.
As far as the language and content goes, my kids don't hear much that they're not already hearing in school. And IMHO, they grew up in a dysfunctional setting with two addict parents, I see no need to hide them from reality and sugarcoat life. Most of the time I don't even think they're paying attention to the speaker, and if they are, I hope they're hearing at least a little of the message that we share in the rooms. Isn't that what we call "leading by example"?
If a parent has to bring their child along to attend a meeting, then I'd rather put up with a little noise than to not have them attend at all. As long as they're working on their recovery, I can suck it up deal with it.