Observed Gaia DR3 [Si/Fe], [Mg/Fe], [Ti/Fe] and [Ca/Fe] abundance ratios versus [M/H] are reported with empty hexagons (the numbers of stars contained in different hexagons are indicated in the legends) are compared with the proposed three-infall chemical evolution model using different nucleosynthesis prescriptions. Model predictions (assuming parameters as reported in Table 1) adopting the nucleosynthesis yields suggested by François et al. (2004) and Romano et al. (2010) are reported with the blue and magenta lines, respectively.