Can I add an extra email address to Scoutbook?

Yes!

Parents are able to add additional connections for their scout(s): for example, another parent, aunt, uncle, or grandparents who are interested in the scout’s progress.

To do this, log into Scoutbook and choose the scout from the ‘My Family’ part of the dashboard. From the scout’s home menu, choose ‘Connections’, and then click ‘Add’.