Wow Georgia. That’s a lot!!
We have a structure where the Marketing Team looks after ‘Marketing’ (outward facing) events and primary / high school are responsible for the events within their departments eg: Formal, presentation nights, grad dinner, internal parent events.
The primary and high schools each have a deputy who has ‘events’ in their portfolio. We get involved in the internal events sometimes to add the ‘gift wrapping’ around the outside to ensure consistent branding, or looking at it from a parent experience perspective. There is always a danger of pressure to take on more of the organisation for these events, but we are aware of that and can push back.
As far as structure of our team is concerned: We are a multicampus school and are growing new greenfield campuses. At a new and growing school, we start with a comms / community liaison person and then when the campus can afford it, add a part time ‘events’ person to the team.