Maryland Code, Labor and Employment § 3-212

(1) is a child of the manager, operator, or owner of the business establishment from or to which a check, money, or negotiable instrument is being transported; or

(2) is transporting a check, money, or negotiable instrument that the minor received as payment for merchandise that the minor delivered or for a service that the minor performed.

(b)(1) A minor may not be employed, between 8:00 p.m. and 8:00 a.m., to transport to or from a business establishment checks, money, or negotiable instruments, including payroll funds or business receipts.

(2) A minor may not be employed, between 8:00 a.m. and 8:00 p.m., to transport to or from a business establishment checks, money, or negotiable instruments that have a value in excess of $100.