Kate tweeted a series of very cute shots of Clemency - her first baby with husband, Michael Heron.
The first shot showed the little lady in a very fetching pink hat, alongside the message:
"Here's the little one - won't tweet too many but just to say hello and thank you for all the well wishes x"
"Clemency at 4 days old - sorry, just v proud and all the more special on a day like today," referring to a Remembrance Day ceremony Kate had taken her new arrival along to.
Kate joins a long list of stars who have shunned big bucks from magazines, choosing to tweet shots of their new arrivals, including Myleene Klass, Kate Hudson, Selma Blair and of course, David and Victoria Beckham.
How adorable is Clemency?
Huge congratulations, Kate and Michael.