(1) The district court did not err when it interpreted the plain language of the Adoption Act’s intervention provision to bar Paternal Grandmother from maintaining her adoption petition because she failed to intervene in Maternal Grandmother’s adoption proceeding. 
(2) The district court applied the intervention provision correctly because barring a guardian and first-in-time petition filer from maintaining her adoption petition for failing to intervene, while harsh, is not an overwhelmingly absurd result from applying the intervention provision.