Contribution of H₂O to 3 H i lines. Left panels: Estimated percentage contribution of H₂O emission to the observed H i transitions—H i (12–7), H i (7–6), and H i (6–5)—across the Class II disc sample. Blue stars indicate the fractional H₂O contribution for each source. Upward green arrows denote sources where the entire flux is attributable to H₂O, while downward red arrows mark sources for which H₂O modelling was not applied due to either dominant H i flux or negligible H₂O emission. Right panels: Violin plots showing the distributions of best-fit physical parameters from LTE H₂O models for each wavelength region. The temperature and effective emitting radius exhibit an anti-correlation, consistent with compact hot inner disc emission dominating at shorter wavelengths. The H₂O column densities remain relatively constant across the different spectral regions.