When one parent is dead, the other, whether of full age or not, may, by last will and testament, appoint a guardian of the person to have the care, custody, and tuition of his infant child, other than a married infant; and if the person so appointed refuses the trust, the Probate Court may appoint another person in his place.
Testamentary guardians of the person
D.C. Code § 21-102 — under Appointment of Guardian; Bond..
D.C. Code § 21-102