Princess Charlotte has a new hairstyle and she looks almost unrecognisable

She's growing up so fast!

The entire Cambridge family stepped out yesterday for Prince Louis' christening at St James' Palace, London.

The day was a quiet, family fair, with members of the royal family and Louis' six godparents in attendance – although the Queen and Prince Philip were absent for this reason.

It was the first time we've seen all three of the Duke and Duchess of Cambridge's children together, and they looked adorable.

Kate Middleton once again wore a cream gown by Alexander McQueen, as she has done with all three of her children's christenings.

However, Louis' mother wasn't the only relative to catch attention for her sartorial choices.

Eager-eyed royal fans also noticed that budding fashion icon Princess Charlotte has a new look, having changed up her hair for the family occasion.

The three-year-old was wearing a centre parting and blue Alice band, and looked so grown up (but still super cute, of course).

Charlotte held her father, Prince William's hand on her way into the chapel along with her almost-five-year-old brother, Prince George.

Amazing how a simple hairstyle change can make someone look so different, isn't it?

We can't wait to see Princess Charlotte's style evolve in years to come.