(a) (1) A CINA petition under this subtitle shall allege that a child is in need of assistance and shall set forth in clear and simple language the facts supporting that allegation.
(2) A voluntary placement petition under this subtitle shall allege that continuation of a voluntary placement is in the best interests of the child or former CINA and shall set forth in clear and simple language the facts supporting that allegation.
(b) A separate petition shall be filed as to each child.