Some speculative research however there is no marriage registered for Thomas
CANNON and Mary Louisa
YOUNG in Tasmania.
Births
CANNON Thomas
Father George Mother Mary DEAN
9 Mar 1850
At Launceston Reg#2656/1850
YOUNG Mary Louisa
Father John Mother Sarah SPENCER
25 Oct 1862
At Launceston Reg#410/1862
Death
CANNON Mary
8 Mar 1897
At Beaconsfield 36 years Reg#13/1897
http://www.rootschat.com/links/0wqc/Launceston Examiner 10 Mar 1897
FUNERAL NOTICE.
The funeral of the late Mrs. Thomas Cannon will leave her late residence,
Patterson-street, on Thursday at four o'clock. Friends are invited to attend.- STORRER, Undertaker, St. John-street.
Did Thomas marry again

There is mention of a Thomas with occupation fisherman in the 1890's. Mary Jane is buried at Carr Villa Cemetery, Launceston. Thomas is not buried with her and I can't find a burial record for Mary Louisa or Thomas.
Burial record for Mary Jane at Carr Villa
http://www.launceston.tas.gov.au/lcc/index.php?c=30&burial_record=6009CANNON Thomas
MILBANKE Mary Jane
8 Jul 1906
At The Manse, York Street Baptist Church, Launceston Reg#883
A possible death
CANNON Thomas
Parents not named
21 Jul 1927
At Lefroy Reg#217There only appears to be one Thomas
CANNON of an age who could have fathered children in the 1890's and that is Thomas who was born 1850.
Marriage
CANNON Thomas 25 years
SMITH Agnes 23 years
12 Mary 1876
At Launceston Reg#512/1876
Birth
CANNON Thomas
Father Thomas Mother Agnes SMITH
22 Nov 1887
At Launceston Reg#688/1887
Death
CANNON Agnes
7 Nov 1889
At Launceston 36 years Reg#441/1889
http://www.rootschat.com/links/0wqb/ Launceston Examiner 8 Nov 1889
CANNON. On 7th November, at her residence, Patterson-street, the beloved wife of Mr. Thomas Cannon, aged 26 years
Funeral Notices
The funeral of the late Mrs. Thos. CANNON will leave her late residence,
Patterson-street. On Sunday, the 10th inst., at quarter-past four o'clock. Friends will please accept this Invitation. DOOLAN, Undertaker, Wellington. street.
Mention of Thomas
CANNON, fisherman, owner of the boat
EDITH in 1886.
http://www.rootschat.com/links/0wqd/Cando
Edit - the 1932 death is a better match for Thomas born 1850.