Margaret -
A lookup of the NSW Pioneers CD turns up only 1 person fitting the exact
details which you supplied.
O'Connor ; Eleanor E
died 1877 Reg'd Newtown
Father William
Mother Ann J
Just using the exact spellings you gave, there are over 600 entries in
the Deaths alone.
There are a possible 11 variations of the name, Eleanor alone,
disregarding the typographical errors and variations in abbreviations
for William and Ann - However you just might have struck it rich.
Have you checked out a marriage of Eleanor Agnes Bryant to a George
Corich (?Court) Betteridge (?Batteries) in 1870 , registered in Sydney.
2 entries for the same event giving variations on what must have been a
near indecipherable entry.