The Ethernet Disk Mini has three shares that will appear when connecting via WebDAV, or SMB:
It is not possible to add more shares. Via the FTP connection, only MyBackup, and MyLibrary will appear. FamilyLibrary does not appear over FTP.
Instead of creating new shares, create new folders. The Ethernet Disk Mini: Home Edition allows for folder level access restriction. Affect the permissions of each folder if security is a concern. Doing so will have a virtually identical setup to control access through share permissions.