We crossed the Nullarbor in both directions 3 years ago with 3 kids and a caravan . I can highly recommend stocking up on food and things like tissues BEFORE you go, everything costs 3 times as much at the roadhouses! Pack lots of snacks and have a portable DVD player handy for the kids, there isn't much to see, but it is really fascinating. Don't drive at dusk, that's when all the kangaroos, etc. come out. We drove only during the daylight hours, but we went as far as possible each day to get across quickly