Hello Stobo,
While looking for information on CJ Hill, I found even more sorrow for Mary Ann.
Just 10 days after the death of R.A.W. Hill at 13 mths of age it appears that she miscarried.
http://trove.nla.gov.au/ndp/del/article/9004933The Mercury Hobart, Tas. Friday 20 January 1882
Births. HILL.-On January 16, at Arthur Circus. Battery Point, the wife of Richard C. Hill, Franklin: a son, Stillborn.
It also appears Pearl, Ruby was born on14 Feb not 14
http://trove.nla.gov.au/ndp/del/article/9102033The Mercury Hobart, Tas. Tuesday 17 March 1885
BIRTHS: HILL.-On Saturday, February 14, 1885, at Oatlands, the wife of Richard C. Hill, chemist: a daughter.
Some good news, I did find that CJ Hill married in 1883 Ida Evelyne Peddar dob. 31/10/1863. they had a son Charles Pedder Hill 1893 Sorell, Tas.
But nothing from there, so far.
The more I delve into Mary Ann's life the more poignant it becomes, if nothing becomes of your search, I would be honoured to be custodian of her medallion.
Robert