As Volcano has already mentioned if the appropriate child restraint system is being used there is no need to disarm the air-bag.
Better still put them in the rear of the car - a much safer location for the cherished little ones. Although it may be awkward on a two door car in my opinion no effort should be spared to protect our children.
A few weeks back I was passing a local Primary School and I was shocked to see how many parents were prepared to transport their children without adequate restraint systems.
See attached link for guidance:-