Tex. Est. Code § 1104.152
(a) A declaration appointing an eligible person to be guardian of the person of a parent's child under Section 1104.053(a) or 1104.103(a) must be signed by the declarant and be:
(2) attested to in the declarant's presence by at least two credible witnesses who are:
(c) A declaration described by Subsection (a)(2) may have attached a self-proving affidavit signed by the declarant and the witnesses attesting to:
Added by Acts 2011, 82nd Leg., R.S., Ch. 823 (H.B. 2759), Sec. 1.02, eff. January 1, 2014.