Reminder to all, when leaving a spot they had spent time in, to look back to check they have taken all their stuff with them.
Callback to:
Where we have been no one can find,
Not a trace have we left behind.
Only the people we’ve helped today
Know that the Brownies have passed this way.
From the Brownie Goodbye Song (origin untraced).
The Brownies are the youth wing of the Girl Guides (US: Girl Scouts) for 7-10 year-olds, an organisation in which Evelyn was active as an adult(?).
Evelyn – 1940s?
Evelyn King (Joyce Collard) – mother of Naomi, Francis, Clare & Jeremy
Another version is slightly different:
Where we have been no-one shall find,
For not a trace we leave behind,
Only the people we’ve helped today,
Will know that a Brownie has passed their way