If you put her name into RYERSON with date range 1878-1940 it gives 17 results, some of which obviously could not be her because of their age, but there are a few possibles.
Including one in 1880, plus one in 1887 aged 49 at Sydney, and one in 1882 at Narrabri, NSW aged 41.
Might be worth looking at
And you can search for those on TROVE, yourself.
Dawn M
The Ellen WRIGHT who died in April 1887 does NOT seem to be the right Mrs WRIGHT.
My transcription
St Stephens C of E, Newtown Burials
17499
Ellen WRIGHT
Abode: Wynyard Square, Sydney
Died 27 April 1887, buried 29 April 1887
Aged 55 years
NSW BDM has #679/1887
Deducing death date from their search engine option gives 27 April 1887
Ellen WRIGHT, parents as Thomas and Mary. Death registered Sydney.
Here's the live link to Ryerson Index :
http://www.ryersonindex.org/ and here's the 1887 mentions:
WRIGHT Ellen Death notice 27 APR 1887 Death 59 late of Wynyard Square, Sydney Sydney Morning Herald 11 MAY 1887
WRIGHT Ellen Death notice 27 APR 1887 Death 49 late of Wynyard Square Sydney Morning Herald 29 APR 1887 http://trove.nla.gov.au/newspaper/article/13657798 SMH 28 April 1887 ....
beloved wife of H.G.A. Wright. http://trove.nla.gov.au/newspaper/article/28348217 SMH 29 April 1887 ....
http://trove.nla.gov.au/newspaper/article/239804491 Tele 11 May 1887 ...
Sadly
Ellen, beloved wife of
Horatio G A Wright, died 27 April 1887 and then their adult daughter Annie died a fortnight later....

This is clearly not your Ellen, wife of John
JM