Sec. 7. (a) Except as provided in subsection (b), the court in which a petition or cross-petition is filed may allow the petition or cross-petition to be amended at any time upon the terms and conditions that the court orders.
(b) The court may not allow a petition or cross-petition to be amended following the deadline for filing a petition or cross-petition under this chapter if the petition or cross-petition as originally filed:
(1) failed to comply with this chapter; or
(2) was not filed before the deadline specified in this chapter.