N.J. Stat. § 9:2-5
In case of the death of the parent to whom the care and custody of the minor children shall have been awarded by the Superior Court, or in the case of the death of the parent in whose custody the children actually are, when the parents have been living separate and no award as to the custody of such children has been made, the care and custody of such minor children shall not revert to the surviving parent without an order or judgment of the Superior Court to that effect. The Superior Court shall have the right, in an action brought by a guardian ad litem on behalf of the children, to appoint such friend or other suitable person, guardian of such minor children, and shall have the right to remove such guardian, and to appoint a new guardian or guardians, and to make such judgments and orders, from time to time, as the circumstances of the case and the benefit of the children shall require.
N.J.S. § 9:2-5