Yes, I eventually noticed the various years and updated my comments accordingly. Just as a helpful suggestion, if folks are adding to a very old original post years later, they might consider starting with, in bold, something along the lines of "Re-visiting this old thread as have recently picked up research again or, if person bumping thread is no original starter, "spotted this old thread and wanted to add a question to it that may or may not be connected to the person being discussed....". This would help make it clear.
Anyhow, welcome back and yes, always helpful to have updates that might aid future researchers too. So, no other clues at all re Catherine? In case you missed seeing in my previous post, have you given consideration to using DNA as a tool to help possibly discover Murphy matches that might lead back to her? Have you looked at 'Catherine Murphy' marriages in the area after 1911 to see if by chance any have the Glenbrook address? Mind you, as the birth certificate states she was a Housekeeper, she may have only been working in and not from Belfast, and of course, may not even have gone on to marry at any time, or could already have been married and widowed. So many possibilities, hence why DNA might prove helpful.