One Twitter user said: "Princess Charlotte completely stole the show she is the cutest little girl and her little wave really did melt my heart". So for now, she's been spending that time hanging out in Kensington Palace with Kate, William, and 3.
The park built miniature versions of the Duke and Duchess of Cambridge, together with their children Prince George and Princess Charlotte and of course the latest addition to the family.
Excitement swept the nation yesterday as it was announced that the Duchess of Cambridge had given birth to a bouncing baby boy.
The Duchess of Cambridge went into labour in the early morning hours and was admitted into the Lindo Wing at St Mary's Hosptial on St George's Day before 6 am.
While four-year-old George has already experienced adjusting to a sibling, it will be Charlotte, who is almost three, who will need to get used to no longer being the baby of the family.
The name of the new baby will be announced in a few days time.
Harry is unlikely to mind shifting down to sixth place.
The same obstetrician, Dr Guy Thorpe-Beeston, and gynaecologist, Dr Alan Farthing, who were present for Kate's previous two births, were also with her to welcome her third baby. Even Prince George and Princess Charlotte dazzled the crowd in their adorable attire - George in his school uniform and Charlotte in a baby-blue dress.
"Buying a present for the new baby to give to his or her older sibling may help".
Kate gave birth inside the Lindo Wing, which offers "world-class" maternity care.
Just as George and Charlotte held onto their dad's hands, Charles held William's hand as they walked up the famous steps of the Lindo Wing.