Mary's family is a large one indeed.
On Trove you will find information on the two brothers in Western Australia. It appears they weren't worried about breaking the law.
Did I mention that when you search for a name on Trove be sure to put the name in between quotation marks " ". It narrows the search. Same when searching on National Archives.
Here you will find the list of immigants on the Severn. Last two columns for the Dimonds and Kavanaghs. You will see that the Kavanaghs were coming out to Thomas.
http://nla.gov.au/nla.news-article115427442Jamjar
Notices for Mary’s lineDIMOND John Joseph Death notice 27-8-1927 Death at Sydney, late of Bondi Sydney Morning Herald 29-8-1927
DIMOND William Robert Death notice 4-12-1947 Death Sydney Morning Herald 8-12-1947
DIMOND Patrick Francis Death notice 15-6-1950 Death at Mater Private Hospital Sydney Morning Herald 20-6-1950
DIMOND Patrick Charles Death notice 23-6-1951 Death Sydney Morning Herald 28-6-1951
DIMOND Katherine Gertrude Death notice 19-1-1961 Death Sydney Morning Herald 21-1-1961
DIMOND Aubrey Kieran Death notice 17-1-1962 Death at Hong Kong, formerly of Sydney Sydney Morning Herald 20-1-1962
DIMOND Ray Death notice 24-2-1970 Death 45 Sydney Morning Herald 26-2-1970
DIMOND Peter Ray Death notice 30-2-1975 Death at Perth Sydney Morning Herald 1-2-1975
DIMOND Thelma Death notice 3-8-1982 Death late of Waverton Sydney Morning Herald 7-8-1982
DIMOND Winifred Death notice 8-2-1994 Death late of Bondi Sydney Morning Herald 10-2-1994
DIMOND Winifred Eileen Death notice 19-6-1996 Death 92 formerly of Bondi Sydney Morning Herald 21-6-1996
DIMOND Peter Anthony Death notice 31-7-1996 Death 81 late of Kincumber, formerly of Paddington Sydney Morning Herald 3-8-1996
DIMOND Joan Mary Death notice 12-8-2008 Death Sydney Morning Herald 16-8-2008
DIMOND Margaret Jane Death notice 18-1-2014 Death 88 Sydney Morning Herald 22-1-2014
COLE Dorothy May Death notice 1-11-1993 Death late of Bondi Junction Sydney Morning Herald 4-11-1993
COLLINGRIDGE Edmund Arthur Death notice 1-1-1966 Death 53 at St Vincent’s Hospital, late of Hunters Hill Sydney Morning Herald 3-1-1966
COLLINGRIDGE Mary Florence Garvan Death notice 24-4-1992 Death 79 late of Hunters Hill, NSW Sydney Morning Herald 27-4-1992
FIRTH Gertrude Madeline Death notice 6-11-1960 Death at Lewisham Hospital, late of Rose Bay Sydney Morning Herald 7-11-1960
HOSEMAN Arthur Murray Obituary 23-8-1972 Publication 64 late of Nambucca Heads Guardian News (Nambucca Heads) 23-8-1972
HOSEMAN Aileen Mary Probate notice 7-9-1983 Publication late of Nambucca Heads Guardian News (Nambucca Heads) 7-9-1983
SHERIDAN Denis Bernard Garvan Death notice 28-6-1922 Publication 49 late of Chatswood Sydney Morning Herald 28-6-1922
SHERIDAN Florence Catherine Death notice 26-6-1964 Death 85 late of Hunters Hill Sydney Morning Herald 29-6-1964
SHERIDAN Florence Catherine Death notice 26-6-1964 Death 85 late of Hunters Hill Sydney Morning Herald 27-6-1964
SHERIDAN Denis Death notice 17-2-1985 Death 67 at Pymble, formerly of Lavender Bay Sydney Morning Herald 18-2-1985
