Tex. Property Code § 115.013

(a) Actions and proceedings involving trusts are governed by this section.

(b) An affected interest shall be described in pleadings that give reasonable information to an owner by name or class, by reference to the instrument creating the interest, or in other appropriate manner.

(c) A person is bound by an order binding another in the following cases:

(1) an order binding the sole holder or all coholders of a power of revocation or a presently exercisable general power of appointment, including one in the form of a power of amendment, binds other persons to the extent their interests, as objects, takers in default, or otherwise are subject to the power;

(2) to the extent there is no conflict of interest between them or among persons represented:

(A) an order binding a guardian of the estate or a guardian ad litem binds the ward; and

(B) an order binding a trustee binds beneficiaries of the trust in proceedings to review the acts or accounts of a prior fiduciary and in proceedings involving creditors or other third parties;

(3) if there is no conflict of interest and no guardian of the estate or guardian ad litem has been appointed, a parent may represent his minor child as guardian ad litem or as next friend; and

(4) an unborn or unascertained person who is not otherwise represented is bound by an order to the extent his interest is adequately represented by another party having a substantially identical interest in the proceeding.

(d) Notice under Section 115.015 shall be given either to a person who will be bound by the judgment or to one who can bind that person under this section, and notice may be given to both. Notice may be given to unborn or unascertained persons who are not represented under Subdivision (1) or (2) of Subsection (c) by giving notice to all known persons whose interests in the proceedings are substantially identical to those of the unborn or unascertained persons.