1) If the car is not being used in the other state for just a short period of time but rather will be "garaged" there and will be regularly used in that state, it must be registered there. 2) If your daughter is going to be a regular or frequent driver, you must add her to your insurance as driver (and pay more for having another driver); if you don't, the insurer will be able to deny coverage. You will also need to be inform your insurer that the car will be kept and used in a different state; they will inform you if that will alter your required insurance and/or premiums (it will almost certainly require that your policy at least meet the other state's minimums)--again, if you fail to do this, you give the insurer grounds to deny coverage in many cases.