The 1903 electoral roll shows Frances TURNER at Rathdown St, Carlton, so that entry in 1903 points to Frances Wells having prior knowledge of that address when she was registering the birth of her son in 1910. The birth registration process was informant driven, the registrar simply recording the information Fanny provided, relying on her honesty re her marriage, the name of the child's father, his own place of birth etc.
Cheers, JM