Her majesty Queen Elizabeth II has sent Jacinda Ardern a private email to congratulate her on the birth of her newborn baby girl.
Thousands of people - including world leaders - have already given their best wishes to Ms Ardern and her partner Clarke Gayford online.
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The Queen's private letter that was emailed to Jacinda Ardern is the latest of warm sentiments that the new mother has received.
The Canadian Prime Minister Justin Trudeau also tweeted today welcoming Ms Ardern to what he called the 'wonderful world of parenting'.
As a tip, he said briefing notes made for excellent bedtime stories.
British prime minister Theresa May tweeted her congratulations yesterday.
The trio will be spending a second night at the hospital and family members are expected to visit them later today.