The extra-wide family RTTs take a special place among the roof tents that offer extra space. The space on offer is of course tempting. Please keep in mind that a tent of the width must also fit on your vehicle, because usually extra-wide mountings are also required as a basic construction. They do not fit on every base rig.
Whereas I think to recognize a fullsize pickup on your profile picture, right? There is probably enough space, right?
One family roof tent that comes to mind off the top of my head is the Eezi-Awn Family 2200, which is really big at 220cm (about 87'') wide. It even has 2 compartments and 2 entrances. Are the Eezi-Awn products distributed in North America?
Another option I've seen many times at overlanding families is simply two roof top tents on the rig. One for the adults, one for the kids. I remember well a family from Belgium that we met in Mongolia a few years ago. They were traveling with a Hilux and two RTTs, one for the adults and one for the two children. The children were fully involved in setting up the camp. Which was great, so they can learn a lot about outdoor activities, camping and overlanding and are busy.