What if the children have their own car insurance in your home?

They are still required to be listed on your auto insurance or excluded from your policy. You really need to consider this before excluding them. The best thing is to put all vehicles on one policy and you get the discounts for everyone. If you exclude drivers in the house that means they are not covered for any reason. In an emergency it will not be alright for the child to drive your vehicle just this time. The exclusion means that there is no coverage if the excluded driver is driving the vehicle.