Bec was also took to social media to share a photo of the adorable bub.
'I can't wait to meet you baby girl'.
The caption continued: 'When sisters have babies it feels like your own (without the sore body parts and sleepless nights). Well done @katetwigley for baking her so well and thank you @matseal for the girl swimmer! 🙈We are thrilled to add a little lady to the army of gorgeous boys in our family 🙌🏽'
Bec’s mate Nadia Bartel also commented on the snap: 'Oh Kate, she is just so so divine. Hope you are feeling good.'
According to a report by the Herald Sun, the WAG is set to miss the Brownlow Medal so she can spend time with the new addition.
However several other reports claim that with the event is being held on Monday 23 September, Bec could still attend.