A. Except as otherwise provided in this subsection, no pupil shall be admitted for the first time to any public school in any school division in this Commonwealth unless the person enrolling the pupil shall present, upon admission, a certified copy of the pupil's birth record. The principal or his designee shall record the official state birth number from the pupil's birth record into the pupil's permanent school record and may retain a copy in the pupil's permanent school record. If a certified copy of the pupil's birth record cannot be obtained, the person so enrolling the pupil shall submit an affidavit setting forth the pupil's age and explaining the inability to present a certified copy of the birth record. If the school division cannot ascertain a child's age because of the lack of a birth certificate, the child shall nonetheless be admitted into the public schools if the division superintendent determines that the person submitting the affidavit presents information sufficient to estimate with reasonable certainty the age of such child. However, if the student seeking enrollment is a homeless child or youth as defined in § 22.1-3, the school shall immediately enroll such student, even if such student is unable to produce the records required for enrollment, and shall immediately contact the school last attended by the student to obtain relevant academic and other records, and shall comply with the provisions of Subtitle VII-B of the federal McKinney-Vento Homeless Assistance Act, as amended (42 U.S.C. § 11431 et seq.), including immediately referring the parent of the student or the youth to the local school division liaison, as described in the federal Act, who shall assist in obtaining the necessary records for enrollment.