Kitkat, I'm going to revise my answer if that's ok
, I got caught up in the Xmas day thing.
As a line manager, my default thinking would be:
School holiday periods where nobody has expressed that they want leave at all = priority for those with school age kids
However, if someone with no children or older children had a reason for preferring their leave then, then I would reassess my default thinking and apply priorities as appropriate - just because someone has school age kids they are not a priority.
Bank holidays are just holidays, so same as above - no special significance attached. (So for the Easter example, a Christian who wanted it for religious reasons would prioritise over 'just' kids).
The only significance for parents of young kids for me is Xmas morning. Xmas morning is when Santa comes, if you celebrate Xmas morning in this way then that edges on priority for Xmas morning.
If a childless employee had an actual reason for wanting Xmas specifically (e.g. family gathering etc), then I would try to find a work round to satisfy everyone (maybe childless employee works the morning, and parent works afternoon).
If it came down to 2 people, both with equally valid reasons, parent or not, then I would make my decision based how much each individual puts themselves out otherwise. E.g. do they offer to cover shifts at short notice falldowns or other 'shit' times, or do they stay quiet and wait until nominated, have they volunteered to work boxing day/New year's eve etc already.
Hope that makes sense!
Thomyorke, that is exactly what I've done my entire career, volunteered to work some things to have a better chance re getting Xmas day off. I often cover call etc for the rest of the Xmas period.
Woozle, please see my explanation above to answer your question.