Tex. Property Code § 181.051: AUTHORITY OF DONEE TO RELEASE POWER.

Unless the instrument creating the power specifically provides to the contrary, a donee may at any time:

(1) completely release the power;

(2) release the power as to any property subject to the power;

(3) release the power as to a person in whose favor a power may be exercised; or

(4) limit in any respect the extent to which the power may be exercised.

Acts 1983, 68th Leg., p. 3724, ch. 576, Sec. 1, eff. Jan. 1, 1984.