It is unlawful for any person under the legal age who, without legal authority, knowingly possesses or knowingly consumes an alcoholic beverage on private property. However, an underage person shall not be prohibited from consuming or possessing an alcoholic beverage in connection with a religious observance, ceremony or rite or consuming or possessing an alcoholic beverage in the presence of and with the permission of a parent, guardian or relative who has obtained the legal age to purchase and consume alcoholic beverages. Nor shall it be a violation of this section for an underage person to possess alcoholic beverages while such underage person is actually engaged in the performance of employment by a person, who is licensed pursuant to N.J.S.A. Title 33, or while actively engaged in preparation of food while enrolled in a culinary arts or hotel management program at a county vocational school or post secondary educational institution.