Carbon-over-oxygen abundance for JADES-GS-z14-0. The left-hand panel shows how the final inferred C/O value changes as a function of the C III]/[O III]88 μm line ratio and of the electron temperature, T_e, under our fiducial assumption of N_e = 100 cm⁻³. The observed and dust-corrected C III]/[O III]88 μm ratios for JADES-GS-z14-0 are marked in green and yellow, respectively. In the right-hand panel, we report our fiducial C/O measurement for JADES-GS-z14-0 on the C/O vs O/H diagram. The oxygen abundance is inferred from the best-fit prospector metallicity reported in Table 2. The C/O value measured in JADES-GS-z14-0 is consistent with pure enrichment from core-collapse Supernovae. We also report for comparison a sample of C/O measurements from JWST compiled from the literature, namely GS-z12 (z = 12.5; D’Eugenio et al. 2024a), GHZ2 (z = 12.34; Castellano et al. 2024), GN-z11 (z = 10.6; Cameron et al. 2024), MACS0647-JD (z = 10.2; Hsiao et al. 2024b), GS-z9-0 (z = 9.4; Curti et al. 2025), ERO-4590 (z = 8.5; Arellano-Córdova et al. 2022), RXCJ2248-ID (z = 6.11; Topping et al. 2024), GLASS-150008 (z = 6.23; Jones et al. 2023), GS-3073 (z = 5.5; Ji et al. 2024). The C/O vs O/H pattern predicted by Galactic Chemical Evolution models of Kobayashi et al. (2020) is shown in blue, whereas the C/O range allowed by the CC-SNe yields from Tominaga et al. (2007) is marked by the golden region.