Right now, your vehicles are insured. But, they are insured for you - not your daughter. You will need to list your daughter as driver on your insurance policy, or you run the risk of having your insurance deny a claim for an accident. Insurance companies want you to list all of the household members who will be driving your vehicles. Insurance companies also want you to list as drivers on your policy those individuals who do not live with you but will be driving your vehicles on any kind of regular or frequent basis. If they do not reside in your household and they occasionally drive your vehicles, you may not have to add them to your insurance policy. The reason to list your 18 year old (and other drivers) is it allows the insurance company know who will be driving your vehicle(s) and allow them to collect the proper premiums. Now, there is really no such thing as "full coverage." Most people use this term to refer to physical damage coverage. Physical damage coverage consists of collision and comprehensive coverage. (Generally, collision insurance covers damage to your automobile caused by collision with another object or by upset. Comprehensive insurance covers damage to your automobile from vandalism, theft or glass breakage.) Most lienholders require physical damage coverage if you are financing or leasing your vehicle. And coverage is just that...coverage. It is not permission for someone to drive. Again, if your daughter is going to be driving your vehicle(s), please call your insurance company immediately to add your daughter on to your policy as a driver.