In New Jersey, like most states, you would need to have collision coverage on your vehicle to claim it through your insurance company. If you did this it is likely that your insurance company would then seek reimbursement from the other party's insurer. This would cause both of you to have claims on your insurance records which could then affect your rates.
If may take more time for you to put the claim through the family member's insurance company but it would generally be the preferable choice in your situation.You might not need a police report, to find out if it is needed contact the insurance companies involved to find out if they will require this to assign blame.