In a proceeding under this chapter, the court shall appoint a guardian ad litem for a child who is a party to the proceeding upon motion of the court or by motion or agreement of the parties. The guardian ad litem shall serve as an advocate of the child's best interests. A

guardian ad litem appointed under this section is immune from civil liability for damages for any act or omission arising out of the guardian ad litem's duties and responsibilities, unless the act or omission constitutes gross or willful negligence or gross or willful misconduct.