Recent research has focused on innovative instructional shifts that aim to expand what constitutes science and engineering practices, exploring also how they can build on students' diverse language resources in science learning. However, few studies explore the intersections of elementary teacher preparation and the implementation of science and engineering practices through expansive and asset-based approaches to language use. Through a qualitative case study conducted within a science methods course at a research university in the southeastern part of the United States, elementary preservice science teachers were positioned as agentive learners, engaging in modeling practices while leveraging their diverse language resources. Using multimodal interaction analysis (MIA), our study examined the meaning-making processes of elementary preservice science teachers in the practice of modeling. Findings revealed three themes related to how the preservice science teachers engaged with diverse semiotic resources: (1) their use of physical manipulatives and other multimodal resources to develop meanings during the initial stages of model development, where they experimented with different ways to represent their understanding; (2) their ongoing reliance on multimodal and linguistic resources for refining and solidifying meanings as the model became more complex and comprehensive throughout the modeling process; and (3) their use of these meanings to interpret and engage with science texts. Implications include the importance of providing elementary preservice science teachers with professional learning opportunities that align with the envisioned science learning experiences of their future students, thus fostering equitable science teaching and learning with models and modeling.