The waiters are friendly with kids, sure. Nice mock cocktails, too, and cool stuff to look at.
But the autmosphere is as kid-friendly as any bar anywhere in the world. People will be drunk, swearing, making off-color comments, and being as obnoxious as people in bars are everywhere (not that everyone is, obviously- I'd like to think I'm not!- but bars are bars).
I'd recommend going early afternoon, and not Friday/Saturday/Sunday. And maybe be aware they may hear some stuff you'd probably rather they didn't.