"Adam-Steward told PEOPLE, "[Harry] laughed and said "five children? - too many".
It was definitely a departure from the dresses and skirts she has worn since she joined the royal family.
Ahead of the outing, Markle did a quick outfit change and emerged with a strikingly different look from her first.
Meghan Markle wore a design by Givenchy.
RSVP, one of Ireland's most popular celebrity magazines, ran a live blog of the visit on Tuesday which was also the top story on the website of the Irish Independent, the country's highest selling daily newspaper.
The Prince sported a crisp navy suit with an azure tie to represent Ireland's Presidential colours, while the fashion-conscious Duchess wore a grey Roland Mouret taupe dress and a pair of black heels. Last on the couples tour was a stop in the Digital Dockland's, where the visited Dog Patch Labs, a co-op space for technology start-ups.
The Duchess and her Duke, Prince Harry, will spend the next two days in Ireland, where the newest-royal will no-doubt continue to lift the style stakes. And if you thought that was bad enough, she didn't stop there, throwing in her two cents on the hair: "I was like, "hold the wisps back - it's a royal wedding for God's sake".
Rachel Marks, 19, said the duchess had also been excited about watching the game, confirming she would be tuning in this evening.
No word yet if the official duties of the Duchess of Sussex will involve meeting more of her adoring four-legged subjects.
They will meet Irish President Michael D. Higgins before visiting an Irish emigration museum, a technology startup hub and Trinity College, Ireland's oldest university.