You know that Ann WILLIAMS married Benjamin BROAD, Hobart 1872 and that Ann WILLIAMS, grandmother, is the informant registering the birth of Benjamin John BROAD, Hobart 1877.
Tasmanian News 12 May 1891 p3
https://trove.nla.gov.au/newspaper/article/163590044?Divorce petitioner Benjamin BROAD, respondent BROAD, co-respondent Richard WEST
...married 1871, four children, lived together until seven years ago….living with Richard WEST in Newcastle.
Ann BROAD has left husband Benjamin and, at 1891, is living in Newcastle, NSW, with Richard WEST.
https://nmclm.com.au/find-a-loved-one/?site_id=6037Search....Last Name WEST
First Name Lila
Date....1951...to...1951
Location....Sandgate
Finds WEST Lila buried 28 August 1951
click the down arrow after the date to see an image of headstone.
This picture of a monument in Sandgate Cemetery, NSW, has names....WILLIAMS...BROAD....WEST.
I think that -
" Ann Elizabeth WILLIAMS, died 14 April 1908, beloved wife of John WILLIAMS of Hobart, age 89 years" is your Ann ASHTON, convicted Edinburgh 1837, arrived Hobart "Atwick", 1838.
Use Trove and Newcastle Morning Herald and Miner's Advocate to find these families.
This seems to be their paper of choice, and notices for deaths, funerals and Memorials appear regularly.
Use BDM NSW to find the deaths.