(a) Whenever a minor under the age of 18 years residing or living with his or her parents is convicted of an offense of this Code for which the court imposes a fine, restitution, or court fees or costs, the parents of the minor shall be jointly responsible for payment of such fine, restitution, or court fees or costs. It shall be an affirmative defense to the obligation created by this section if the parent demonstrates to the court that, at the time of the offense, either:

(b) For the purposes of this section only, the term "emancipated minor" means a minor over 15 years of age and under 18 years of age who has, with real or apparent assent of his or her parents, demonstrated his or her independence from his or her parents in matters of care, custody, and earnings. The term may include but shall not be limited to any such minor who has the sole responsibility for his or her own support, who is married, or who is in the military. A person who fails to pay any court-ordered fine, restitution, or court fees or costs shall be subject to section 50-39. (Code 1979, § 23-26.5)