Tex. Estates Code § 124.052

(a) This section applies to an executor, administrator, or trustee authorized under the will or trust of a decedent to satisfy a pecuniary devise or transfer in trust in kind with assets at their value for federal estate tax purposes, in satisfaction of a gift intended to qualify, or that otherwise would qualify, for a United States estate tax marital deduction.

(b) Unless the governing instrument provides otherwise, an executor, administrator, or trustee, in order to implement a devise or transfer described by Subsection (a), shall distribute assets, including cash, fairly representative of appreciation or depreciation in the value of all property available for distribution in satisfaction of the devise or transfer.