There is a dirt road entrance into Arches from the north that is good for kids and one or two challenging spur trails where you need rock sliders.Well, I drove to Moab! I'm currently spending the next couple nights here. I'm here with my family to see some of the sights and national parks but I'm hoping to get the FJ out and wheel, even if it is on a simple trail!
There is also a relatively easy 4x4 only trail adjacent to The Great Arch parking lot that I let my son and daughter drive through. They loved it.
Moab Brewery downtown is family friendly and has pretty decent grub. They also brew their own draught rootbeer.
All these things are highly recomended if you have younger kids and can't make all the more famous named and challenging trails. Of course, if you can sneak away from the fam for a few hours and join up with some other drivers, I recommend that as well!