She said: "He didn't want to stop and I said 'please just have the scan'.
"Despite all his wonderful ways, Robin could be very stubborn and he never liked bad news - he just didn't want to know.
"He went to do a show in New Zealand as they'd just experienced an earthquake.
"Maybe it was very important for him to do that show, but it was still important for him to have his scans."
Gibb played three shows on that November tour, in Auckland, Wellington and Christchurch with support act The Pointer Sisters.
The songwriter toured for more than a fortnight during November that year and Mrs Gibb said the cancer had developed into a secondary stage.
By the time he had a check up the tumour had spread to blood vessels.
His last days were cherished by his family.
"We ended up having a wonderful few weeks with him," Mrs Gibb said.
- PAA