Good afternoon Sarah
Type "Selina Stanley" (exactly as I have including the inverted commas) into TROVE which is the National Library of Australia digitised newspapers. You will get lots of hits with several reports of her death in various newspapers. Some newspapers report more details than others. It's most interesting indeed.
Sorry I don't have NSW Police Gazette access
Happy researching and hope this helps
By the way, more modern 'metho drinkers' flavour it with fruit cordial but it beats me how they can swallow it!
Gerry