Texas Estates Code - EST § 1104.054. Selection of Guardian by Minor

(a) Notwithstanding any other provision of this subchapter, if an application is filed for the guardianship of the person or estate, or both, of a minor at least 12 years of age, the minor may select the guardian by a writing filed with the clerk, if the court finds that the selection is in the minor's best interest and approves the selection.

(b) Notwithstanding any other provision of this subchapter, a minor at least 12 years of age may select another guardian of the minor's person or estate, or both, if the minor has a guardian appointed by the court, by will of the minor's parent, or by written declaration of the minor's parent, and that guardian dies, resigns, or is removed from guardianship.  The minor must make the selection by filing an application in open court in person or by an attorney.  The court shall make the appointment and revoke the letters of guardianship of the former guardian if the court is satisfied that: