Sydney Burns BARNARD died in 1984, "late of Guildford" (Sydney). I can't see a death for Rhoda so it must be after Nov 1992. She was born in 1911, so I assume she is not still living. Will keep looking for a death notice, but can't readily see one in Sydney.
Added - there is a family tree on Ancestry that has her death on the Gold Coast, Queensland, but no date or source. The same tree has a death for Irene WALKER DUN in 2010, but again, no source.