Tex. R. Civ. P. 44

As amended through August 21, 2020
Rule 44 - May Appear by Next Friend

Minors, lunatics, idiots, or persons non compos mentis who have no legal guardian may sue and be represented by "next friend" under the following rules:

(1) Such next friend shall have the same rights concerning such suits as guardians have, but shall give security for costs, or affidavits in lieu thereof, when required.
(2) Such next friend or his attorney of record may with the approval of the court compromise suits and agree to judgments, and such judgments, agreements and compromises, when approved by the court, shall be forever binding and conclusive upon the party plaintiff in such suit.

Tex. R. Civ. P. 44