What a beautiful thing - a home full of singers! Your whole family can save their individual progress with up to 5 profiles on the same account. First, make sure to create an account with your email.
When you first install the app, if you create an account with your email, you can create your first profile. To add more profiles, just press the avatar at the bottom right corner of the add. Then, at the top of the screen, you'll the option "Add Profile".