The newlywed, who announced that she is pregnant on Tuesday morning, beamed at the camera while she promoted the World Childhood Foundation's new campaign, 'Thank you'
At the launch of the new campaign mum-to-be Madeleine paid tribute to her own mother Queen Silvia of Sweden, who founded the charity, and her sister Princess Victoria.
"I want to thank you both," said Madeleine. "Victoria, you have helped me during all these years. When we were children and mum and dad had to go out, she [Victoria] always distracted Carl Philip [her brother] and I if we were sad and missed our parents.
"Victoria means a lot to me, she is an amazing older sister."
Speaking to the charity's guests, who had gathered at the headquarters of the Swedish music firm Spotify for the event, Madeleine said that her pregnancy is going well.
"I feel fine," said the princess as she chatted to the invitees.
Given that Madeleine is only in the early stages of her pregnancy their was no bump to be seen. The 31-year-old wore black skinny jeans, a loose blouse accessorised with a jewelled collar necklace and a dark green blazer.
Princess Madeleine divides her time between Sweden and New York, where she worked for the foundation.
Just as her sister did during her pregnancy, Madeleine plans to continue as far as possible with her scheduled royal duties – including appointments for the World Childhood Foundation.
"No changes to the schedule of Madeleine's engagements," read a statement from the royal palace. "Work for Childhood is planned during the fall of 2013."
It was in the Big Apple that Madeleine met financier Chris O'Neill and the pair were married in June.
In July, fresh from their romantic Seychelles honeymoon, the royal sidestepped questions about their plans to start a family, saying: "Right now we are enjoying our life as newlyweds."
But there may have been a clue as to the forthcoming announcement in the pair's comments that they were "still in paradise".