This paper presents a numerical investigation of the structural behavior of stay-in-place textile-reinforced concrete (TRC) formworks used in a novel semi-prefabricated slab system. These formworks, designed to reduce self-weight and facilitate on-site assembly, are characterized by a thin-walled geometry reinforced with AR-glass fabrics and are subjected to critical loading during transient construction phases. The study focuses on the simulation of meso-scale material tests and full-scale experiments conducted under a centered point load, representative of a scenario such as the passage of operators during assembly. Three modelling strategies are adopted: a smeared shell approach, a discrete model with explicit representation of the textile reinforcement, and a composite layup approach. All models are implemented in a nonlinear finite element framework, including tensile cracking and the full trilinear behavior of the TRC material. The aim is to explore how textile orientation and positioning within the shell thickness affect the global response, crack development, and ultimate capacity of the formworks. The comparison between the three modelling strategies is intended to assess the ability of each approach to capture global stiffness, collapse mechanisms, and local effects such as crack localization and textile rupture. The outcomes of this study point to the potential and current limitations of numerical modelling strategies in predicting the response of TRC elements under realistic load conditions. These findings open the way for future optimization of reinforcement layout and thickness distribution, with the broader goal of improving mechanical performance while maintaining lightweight construction.