I'm sorry as well Tony. It seems we have taken you in a wrong direction but perhaps because we made assumptions, as you posted such general information originally, without any detail. I think sancti, Chris5856 and I were all under the impression that you were trying to track down her death so that you could find her burial. Your initial mention of 'about 60 years ago' led us to think we needed to identify her name and date of death for you before you could find her burial, if you can follow that, and that's what we were doing. We didn't appreciate that your mother already had the death certificate.
Chris has done a huge amount of work on St Joseph's, Aidrie and when he's back on the board he may be able to look her details up for you - if you remember, when he was last on he asked for her name and date of death.
If she wasn't buried in St Joseph's then you probably need to approach the cemeteries around the area (using the links Monica posted) and ask them to search for you. Good luck with it