I am stuck

I am trying to find the death of Ann DONALD born 19/1/1858 Gopmburra, QLD Parents are George DONALD and Hannah HUGHES
Ann married William Joseph BARR in 1880. He died in 1891 in Ipswish, QLd
Ann next married William Alfred Walter in 1895
Both marriages have her as Annie and not Ann
I have info saying she died 10/5/1907 in Dalby QLD but can find no death for her on the BDM site
I can not find the death under Barr or Walter
Does anyone have any ideas where to check next
Newbe