Sec. 2. The department, after negotiating with:
(1) the child's parent, guardian, or custodian;
(2) the child, if the child is at least fourteen (14) years of age; and
(3) any child representatives selected by the child under section 7 of this chapter;
shall complete a child's case plan not later than sixty (60) days after the date of the child's first placement or the date of a dispositional decree, whichever occurs first.