The Cambridges appeared outside the hospital when each child was born.
When Prince Louis was born in 2018, Kate made a link to the birth of Princess Charlotte.
Princess Charlotte was seen for the first time wearing a small white knitted bonnet.
It was thought to be a gift from the children’s nanny Maria Teresa Turrion Borrallo.
Maria has reportedly been with the family since Prince George was just eight months old.
Prince Louis also wore the handmade garment during his first appearance, however it was styled differently.
Princess Charlotte reportedly wore the cap the opposite way from how it was designed to be worn, while Prince Louis wore it the right way around.
Kate stood for a photo call on the day that each of her children were born.
“Everyone had been so supportive, and both William and I were really conscious that this was something that everyone was excited about,” the Duchess added.
“And, you know, we’re hugely grateful for the support that the public had shown us, and actually for us to be able to share that joy and appreciation with the public, I felt was really important.
“But equally it was coupled with a newborn baby, and inexperienced parents, and the uncertainty of what that held, so there were all sorts of mixed emotions.”
The royal posed outside the hospital after giving birth to all three of her children.
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The royal line of succession – who outranks who?
The line of succession to the British throne dictates the order in which each member of the Royal Family would ascend to the throne.
It is also seen as a ranking of importance with the head of the line, the Queen, taking the place of ruler.
Older children come before younger children. Traditionally boys came before girls, but this law was changed on 26 March 2015 before the birth of Prince William’s first child.
Incredibly, Catholics are still excluded from the line of succession, as are children born outside of wedlock.
The royals, who usually stick to a strict protocol when appearing in public, often arrive at events in ascending order of importance, with the most important royal arriving last.
Prince Charles, 71, is currently second-in-line to the British throne, followed by Prince William, 38, his oldest son.
Then comes Prince William’s children, George, seven, Charlotte, five, and Louis, two, and they are followed by Prince Harry, 35. Prince Harry is succeeded by his son Archie Harrison, born in May 2019.