Don't know if you have already gone, in which I'm too late, or you're going Sunday, but I went to the WGH in Edision this morning, and it definitely was kid friendly (and yes, there was a very long line for the Thomas ride). Crowds were humongous, and ages seem to run 1 --> 13 ... 30 --> infinity (only teens I saw were helping their parents in the vendor areas).
There are a number of operating layouts: the N scale guys put all their modules together, and had one humongous layout (They also demonstrated the true purpose of Z-scale by using some Z-scale buildings for Forced Perspective in one of their city scenes). I think there was 1 O guage 2-railer layout, 2 O 3- railer, 2 large HO setups, the Humgo N-scale layout out I mentioned, 1 S(illy) scale, and A Garden module layout (again, all of these were fairly well sized modular setup, and had modules of differing scenery and levels of completeness, but on the whole everything was pretty good) - these modular layouts are on the other side from the entrace lobby, near the 'Expo Cafe'. There were also lots of small operating layouts thru-out the center displaying manufacturers's and vendor wares, for example City Classics had an urban diorama display showcasing their structures and with a automated switcher movering back and forth between tracks, and while I was getting some pictures (I have several City Classic kits, and I wanted to see the finished products), I overheard a number of people impressed by and complimenting the modeling - this occurred at other dioramas too. (I myself was impressed to see an O scale intermodal train going aournd what looked like a 2' foot of track - how the heck did it keep from derailing?). Walthers had a booth especially for small Kids, dunno what they did (looked like Biro track), and I also saw kids w/ paper Walthers Engineer caps, so I suppose they ties together. Shout-out to Otto - I think there was at least 5, maybe 6, Atlas Passenger Stations on the 2 HO layouts - and innumerable quantities of "Aunt Millie's" house derivatives.
The vendors...eh, I remember the 2004 show (perhaps I misremember, that was over 6 years ago) as having more manufacturers directly selling their own stuff - this show seemed more like a flea market approach with MSRP prices (is that every train show nowaday?s). There was plenty of non-railroad stuff (especially Hot Wheels), and Star Wars actions figures (did little kids even like Star Wars anymore - Revenge of the Sith was 5 years ago...). Sadly, the technology that gave us micro-LEDS for our layouts also gave us the Light-Up baseball caps sold at the show (ugh - unintended conseqeuences indeed). Even the 'Tool Man' had nothing I really wanted, at least at the prices he was offering (maybe there will be discounts come late Sunday, I dunno). So, your spouse may indeed heartily approve - you and your kids will have lots to see, but you might not end up buying all that much.
I got there about 10:30AM, and parking was already ugly (I ended up in Field B, right off Raritan Centre Parkway, rather muddy), and crowds of people with toddlers, infants, strollers etc swarming toward the Expo Center. I don't remember any seats or benches outside of the Expo Cafe area, so keep that in mind if you have kids that tire easily.
Top Gear Top Tip: Aim for the Restrooms by the Lobby entrances versa the ones by the Cafe - seemed like shorter lines. Also, Big Train Sound is indeed, BIG TRAIN SOUND - you'll see...I mean hear. Oh, and the Brooklyn modelers get 2 demerits for their silly 'Finger Bucket' - Losers!
i hear ya about that Atlas depot, though!!