If upon the examination prescribed by section 35 of this title, it appears that the male or female applicant is under 18 years of age and has not been previously married, the court shall not issue a license unless the father of such person, or if there be no father, the mother, or if there be no father or mother, the guardian, shall consent to such proposed marriage, either personally or in court, or by an instrument in writing attested by a witness and proved to the satisfaction of the court.