California Code, Family Code - FAM § 8916

(a) If the petitioners move to withdraw the adoption petition or to dismiss the proceeding, the court clerk shall immediately notify the department at Sacramento of the action. The licensed adoption agency shall file a full report with the court recommending a suitable plan for the child in every case where the petitioners desire to withdraw the adoption petition or where the licensed adoption agency recommends that the adoption petition be denied and shall appear before the court for the purpose of representing the child.

(b) Notwithstanding the petitioners' withdrawal or dismissal, the court may retain jurisdiction over the child for the purpose of making any order for the child's custody that the court deems to be in the child's best interest.