If she is emancipated, you need to let the doctors', hospitals, etc know that while she is on your insurance, you are not financially responsible for her bills. It's not the insurance company that is charging you (outside of the premiums paid each month by your dh's employer and himself) but rather the service providers. Probably because she is 17 they think you are responsible -- have you in the past signed for that responsibility for those doctors? If so, you might at least revoke it for any further copays, cost sharing, etc.