(a) A child support order for more than one child shall provide that, on the termination of support for a child, the level of support for the remaining child or children is in accordance with the child support guidelines.
(b) A child support order is in compliance with the requirement imposed by Subsection (a) if the order contains a provision that specifies:
(1) the events, including a child reaching the age of 18 years or otherwise having the disabilities of minority removed, that have the effect of terminating the obligor's obligation to pay child support for that child; and
(2) the reduced total amount that the obligor is required to pay each month after the occurrence of an event described by Subdivision (1).