Del. Code tit. 13, § 1906

A child custody determination made by a court of this State that had jurisdiction under this chapter binds all persons who have been served in accordance with the laws of this State or notified in accordance with § 1908 of this chapter or who have submitted to the jurisdiction of the court, and who have been given an opportunity to be heard. As to those persons, the determination is conclusive as to all decided issues of law and fact except to the extent the determination is modified.