Tex. Est. Code § 1203.152

When the court is notified of the existence of a proposed successor guardian under Section 1203.151(a), or the court otherwise becomes aware of a family member, a friend, or any other interested person who is willing and able to serve as a successor guardian for a ward of a guardianship program or governmental entity, the court shall determine whether the proposed successor guardian is qualified to serve under this title as the ward's successor guardian.