Tex. Loc. Gov't Code § 250.009

Notwithstanding any other law, a municipality, county, or other local public health authority may not adopt or enforce an ordinance, order, or rule that prohibits or regulates, including by requiring a license, permit, or fee, the occasional sale of lemonade or other nonalcoholic beverages from a stand on private property or in a public park by an individual younger than 18 years of age.