You control what Family Members invited to have accounts on Cubby can do within your Cubby Family.
The three levels of access are as follows:
Admin - Can create, update and delete content within your Cubby Family.
Editor - Can create and update content within your Cubby Family.
Viewer - Can only view content within your Cubby Family.
When you add a Family Member, the permissions are defaulted as follows but can be changed after the Family Member is added:
Parent = Admin
Kids & Cared For = Viewer
Collaborators = Viewer