Sec. 3. (a) A child custody proceeding is commenced in the court by:
(1) a parent by filing a petition under IC 31-15-2-4, IC 31-15-3-4, or IC 31-16-2-3;
(2) a person other than a parent by filing a petition seeking a determination of custody of the child; or
(3) a child, by the child's next friend, if the child is the subject of a:
(A) child in need of services petition under IC 31-34; or
(B) termination petition under IC 31-35.
(b) As used in this section, "child's next friend" means:
(1) the department;
(2) the child's court appointed special advocate; or
(3) the child's guardian ad litem.