Another person said: “Congrats Rhian, How are you back so quick to being so skinny??”

A third added: “Enjoy every minute. You look great Mumma xx,” and a fourth said: “Awww rhian you look amazing.”

Last month, the star confirmed the news on Instagram that she had welcomed a baby boy as she shared a sweet first picture of the newborn tot.

She captioned the post: “All my boys! My life is complete!

But just one week on, Rhian, 37, has astounded fans with a new photo cradling the tot and revealing her small waist.

Rhian looked cosy in a pair of green joggers and a white top as she doted on her baby boy.

She wore a minimal makeup look and her hair down, and penned: “Beautiful Boy! Already a week old!! Madly in love!”