It's the age old question that plagues families: When do you know you're done having children?
And for the Duke and Duchess of Cambridge it looks like they may not be done with nappies just yet with a fresh report from Us Weekly claiming the royal couple are "trying" to conceive their fourth child.
"Having four children was always part of Kate's plan," a source reveals in the new issue of the American publication.
"She put the idea on hold when [the coronavirus pandemic] hit, but now there is light at the end of the tunnel with the vaccine and [Prince George and Princess Charlotte] scheduled to return to school in April. She feels ready to start trying again."
The couple are already the proud parents to Prince George, seven, Princess Charlotte, five, and Prince Louis, two.
However the concept of a fourth baby wasn't an easy decision to make.
"It took a while for Kate to convince William, though," the insider explains.
"He said that three children is more than enough. The thought of having four made him feel overwhelmed… But Kate's desires to have another child have inspired him, and at the end of the day, he loves and appreciates the secure family setting he never had growing up. Why not make it bigger? After taking some time to think about it, he's on the same page and is excited about the future."
There's no doubt the couple weighed up the implications of Duchess Catherine, 39, having to go through another pregnancy as she has suffered from Hyperemesis gravidarum (HG, or extreme morning sickness) with all three of her previous pregnancies.
Hyperemesis gravidarum is an extreme version of pregnancy nausea or sickness. It can include severe vomiting, usually in the first 20 weeks or so, where you can keep little or no food down. Catherine has had several trips to the hospital with the debilitating illness.
But according to the source, the Duchess' desires to have another daughter override any illness she may have to face.
The insider says the Duchess would love Charlotte to share the same bond that she does with her younger sister Pippa Middleton, 37.
"She wants Charlotte to have the same enjoyable experience — to grow up with a little a sister to confide in and look out for," the source says.
It's not the first time a fourth baby has been suggested.
In 2018, Princess Diana's former butler Paul Burrell told Now To Love he predicted William and Kate would be just like The Queen and Prince Philip and have four children.
"There will be one more! There'll be four, they want four and there'll be four babies for William and Kate. Just like The Queen, there was a gap between her [two kids] but William and Kate are running out of time, so they better get on with it," he told us at the time.
Watch this space!