Texas Family Code - FAM § 101.003. Child or Minor;  Adult

(a) “Child” or “minor” means a person under 18 years of age who is not and has not been married or who has not had the disabilities of minority removed for general purposes.

(b) In the context of child support, “child” includes a person over 18 years of age for whom a person may be obligated to pay child support.

(c) “Adult” means a person who is not a child.