The Prime Minister's wife updated her Instagram followers on her second child's birth last Thursday.
Romy Iris Charlotte Johnson was her full name.
For Romy, Carrie chose her aunt Rosemary, Iris the Greek word for rainbow, and Charlotte the late Mr Johnson's mother.
Her husband exposed the name to the press during a visit to a vaccination centre in Kent.
A woman in queue for a jab asked him about his name.
On December 9, a ‘healthy baby girl' was born in a London hospital.
So Wilf has been ‘stroking Romy's hair, giving big hugs and playing with his matchbox cars right next to her crib,' Carrie recalled.
‘We are extremely appreciative', she said, thanking the maternity team at UCLH for ‘looking after us so well'.
Rumours of illegal parties and gatherings at Downing Street and other government and Conservative Party properties last year sparked Romy's birth.
Her father has also had to make difficult choices on the current Covid type, Omicron, which many believe will be the worst yet.
The Prime Minister is believed to be taking time off for Christmas with his family but not paternity leave.
Sein prior marriage to Marina Wheeler had four children and a daughter with art expert Helen MacIntyre.
He previously had to deny asking affluent Conservative Party contributors for help paying for Wilf's nanny.