Current practice is they share a simple generic login i.e. Y1 and all students use the same account.
Schools will continue to have choice over how younger students and their devices authenticate to the system. The school will receive the most value from functionality and analytics if each person logs in with their own personal CEWA account. There will be genuine cases where it is not practical or proper for this to occur and schools will have an interface to create and manage generic CEWA Identity.
With some devices it may be possible to use facial recognition or other biometric authentication, and schools will be advised of their options and best practices.