She's now a mother-of-two – a prince and a princess – who both arrived within less than two years of one another.
And although little Charlotte is not yet six months' of age, excited news organisations in the US are convinced that royal baby No.3 is ALREADY en route.
Yes, if Stateside rumour is to be believed, Duchess Kate is now pregnant, with the little bundle of regal joy arriving next spring.
The fact that she was seen holding aloft glasses of champagne at the recent royal banquet in Buckingham Palace – not to mention that on the same occasion her bespoke Jenny Packham dress showed no hint of a baby bump – seems to have been disregarded.
Instead, the covers of more than one glossy magazine this week declare that the wife of Prince William is very much expecting.
"It seems Kate Middleton, 33, and Prince William, 33, wasted no time getting back into the swing of things," declares one popular US site.
Meanwhile, Life & Style magazine, which carries the story on its front-page this week, says: “They’re expecting! It happened far quicker than they expected – they’d just started trying for another child. But William and Kate are so excited".
That publication furthermore says: "Friends are saying the baby will arrive around June. They say Kate is at the very beginning of her pregnancy and won’t show any sign of a bump until next year. She still looks extremely slim."
And as far back as early September, Star magazine was also stating that the Duchess was "in the early stages of pregnancy with baby number three". It added that the new addition to the Cambridge family is due "in late April or early May, so she’ll likely be showing by the New Year".
Even earlier in the summer, some US outlets reported absolutely that Kate was eager to have three children by the time she turned 35: as she celebrates her 34th birthday in January, it seemed she was eager to get a move on.
The rumour may all, of course, seem a little far-fetched, but Wills himself did say in the aftermath of Charlotte's arrival that a third Cambridge child was certainly possible.
In an interview to mark his first day as an air ambulance pilot, the prince spoke of family-life. When the interviewer playfully hinted at another baba, the second-in-line to the British throne laughed: "We've only just had the second one!"
Though he then added with a smile, "but you never know what's going to happen in the future."