If a person named as executor in a will is at the time of the probate thereof under the age of eighteen (18) years, the other executor or executors, if any qualify, shall administer the estate until the minor arrives at full age, when, upon qualifying, he or she may be admitted as a joint executor of the will. If no other executor shall qualify, administration may be granted with the will annexed during the minority of the person named as executor and until he or she shall qualify.