There is a Marion Kelly Young (number 2315) buried in the cemetery beside Celtic Park (Janefield or the Eastern Necropolis they call it) but there is no death date, and I suspect because of that it may be a much older grave.
There is also a Catherine (Risk) Young (number 2313) died 30th Sep 1846 aged 66 and a Jean (Aitken) Young (number 2314) buried there, probably her relatives.
Try a google for Memento - Mori, Scotland, and a site for some graveyards in Glasgow and the surrounding districts comes up. Click it. ...Then see "Search Locations Indices" on right of the page that comes up. You will see St Peters on the list but her name isn't there. I also tried others and didn't see her.
The problem is that the records aren't always reliable. A person can be buried in a graveyard and might not be showing on the records. You really have to know where the person was buried and then contact that church or perhaps the Glasgow City Council and ask there for the records.
Also, although she was living at Nuneaton St, she may have been brought up in another area of Glasgow, and there might be a family grave there.
You could ask your friend if she knows if Marion Young had any connection with the name Kelly.