Hi Si,
I'm sure you'll have a great time, the LT events are full of people of all ages and interests, and you should find something for all of you to get involved with, if you take the trouble to wander around and speak to people.
I wouldn't say there';s any particular faction that is good (or not) as far as child-friendliness goes. The Tarantula faction tends to be more of a nighttime faction and quiet in the mornings, if that makes a difference, but even then that's a generalisation, there are many exceptions.
As you mentioned, these boards are pretty quiet at present, and that's probably a symptom of Facebook pages getting a bit more attention. There are Facebook pages for LT itself, as well as guilds and factions. You might get a bit more response from that route.
My own faction (the Bears) is holding an event between LT events, during March. The official term is "Sanctioned Event" - the event isn't run by LT itself, but is typically arranged and organised by a faction or a guild, who then apply to LT for official sanctioning to use the LT rules and background.
So. have a look at Facebook, ask questions, and buy a couple of drinks for T!