It was one of the first times since announcing her pregnancy that she showed off her baby bump.
Also Tuesday, Markle and Prince Harry stepped out onto their hotel room balcony to greet well-wishers in Fiji Tuesday.
It was the latest stop of their tour Down Under and the duke and duchess recreated the balcony moment his grandparents first did in 1953 when Queen Elizabeth II and Prince Philip stayed at the same hotel room.
The duke and duchess received a traditional island welcome, complete with dancing. Harry even sipped some kava, Fiji's unofficial national drink.
The duchess had her arms protected with long sleeves as she arrived in Fiji, apparently to ward off any mosquitoes that could carry the Zika virus.
Zika can cause birth defects and pregnant women are warned not to travel to foreign destinations where it is a problem.
Taking precautions, the duchess is not expected to join Prince Harry when he visits a local rainforest Wednesday.