does child support end when child turns 18 or when child graduates high school?

Child support ends when the child turns eighteen or graduates from high school whichever is later.  If over eighteen, the child must be enrolled under Chapter 25 of the Education Code in an accredited secondary school in a program leading toward a high school diploma; or under Section 130.008 of the Education Code in courses for joint high school and junior college credit; or on a full time basis in a private secondary school in a program leading toward a high school diploma and the child must be complying with the minimum attendance requirements of Subchapter C, Chapter 25, Education Code; or the minimum attendance requirements imposed by the school in which the child is enrolled, if the child is enrolled in a private secondary school.  Please check with a family law practitioner in your area for advice on how to proceed.