During February 2025, Lucía Pelegrina enhanced heavy neutral lepton (HNL) decay modeling in the SBNSoftware/sbncode repository by implementing anisotropic decay distributions, polarization handling, and three-body angular rotations within C++. She integrated the CLHEP random number generator and disabled interference in two-body decays to improve simulation fidelity. Lucía also aligned HNLMakeDecay configuration in SBNSoftware/sbndcode, ensuring reproducibility and maintainability across repositories by updating FCL configuration files. Her work demonstrated depth in configuration management, event generation, and physics simulation, resulting in more accurate and consistent HNL decay modeling for particle physics analyses while supporting easier cross-repository maintenance and analysis reproducibility.