Once outside their school, you'd expect 'grown up' pupils to maintain the same safe distancing as the rest of us, ie two metres wherever possible. As others suggest, the school needs to explain this important distinction to their students and the reasons for it. I don't think the 'rule of six' applies, as walking from place to place on the pavement isn't really a 'social gathering', despite many school students regarding it as such.
Peter Evans ● 1291d