In Estate of Keener, two heirs of a trust settlor filed an application to declare heirship. No. 13-18-00007-CV, 2019 Tex. App. LEXIS 1222 (Tex. App.—Corpus Christi February 21, 2019, no pet. history). The beneficiary of the trust filed a plea in intervention in the heirship proceeding, but the trial