Royal Baby Girl: Princess Charlotte of Cambridge's First Pics

Kate Middleton walked into St. Mary Magdalene Church holding Princess Charlotte on Sunday, July 5, 2015. The Duchess of Cambridge's royal daughter was baptized there by the Archbishop of Canterbury.

Look at that sweet smile on George! Someone's happy to be a big brother.

Kate took these precious photos of her two children in mid-May.

"We're delighted to share the first photo of Prince George with his little sister Princess Charlotte," the official tweet from Kensington Palace read.

How sweet is George giving his sister a kiss on the forehead?!

The Duchess of Cambridge looks positively giddy showing off her daughter. We just can't believe that's the face of woman who gave birth just 10 hours ago!

The new parents gaze at their daughter.

Prince William and Kate Middleton in front of the hospital with their new baby daughter.

A glimpse of face of the as-yet-unnamed Princess of Cambridge.

Because we just can't get enough of the little princess!

And just like that the Duke and Duchess of Cambridge leave the Lindo Wing of St. Mary's Hospital. From check in to check out, it took 12 hours.

The prince gives the crowd a wave as they debut their new baby girl.

George prepares to meet his baby sister, but first a regal wave to crowds outside St. Mary's Hospital. And, can we talk about how cute the father-son duo are in their matching sweaters!

But seriously, cutest big brother ever!

As the adorable matching princes head back into the hospital, William plants a cute kiss on his son's forehead!

Shortly following the birth of his new daughter, the prince exited the Lindo Wing of St. Mary's Hospital to fetch the couple's 21-month-old son. "I'm going to pick up George," he sweetly told the crowds outside.

Though the official birth announcement was made on Twitter (oh, how modern!), the traditional easel was still placed in the forecourt of Buckingham Palace to mark the arrival of the new princess. 

Following the announcement of the royal birth, unofficial town crier Tony Appleton stood outside the hospital to declare, "We welcome with humble duty the new baby of their Royal Highnesses the Duke and Duchess of Cambridge. The princess is fourth in line to the throne."

NEXT GALLERY: Prince George's Most Adorable Pics