The Love Actually star posted the picture of her firstborn to Instagram, with the caption:
"Me and Mummy having giggles in make up @itvthismorning x."
Martine is one of three judges for the show's Babyface competition, which is now down to six semi finalist babies following a nationwide search.
The 38-year-old previously told Hello! magazine:
'I used to think, when I heard people say having a child was their most life-changing moment, that they were just saying that because it was the expected thing to say.
'Now I so get it. I have never been so in love, so content and so full of happiness in my life. My mum always said to me that it is a love like no other, and it’s absolutely true.'
She added: 'This baby boy is the love of our lives and I think the fact this didn’t happen easily for us and faced challenges along the way has made him even more precious.'
The actress welcomed her son with back in February with her husband Jack McManus into the world in February and has kept a relatively low profile since.
So cute!