Paris Hilton "always wanted" a little girl.

The 42-year-old heiress already has 10-month-old Phoenix with husband Carter Reum but the pair announced earlier this week that they had welcomed daughter London and now an insider has explained that they are "thrilled" to have become parents once again.

A source told UsWeekly: "Paris and Carter are thrilled to welcome London into their family. They have always wanted a little girl."

The former 'Simple Life' star initially sparked speculation that she had become a mother for the second time earlier this week when posted a picture of a pink outfit emblazoned with the word 'London' - which she has repeatedly said she would choose as a name if she had a little girl - alongside a pair of tiny red sunglasses and a teddy bear.

She captioned the post: "Thankful for my baby girl (sic)"

And amongst the photos from her Thanksgiving celebrations shared to her Instagram Story, Hilton also posted a picture of Phoenix which was captioned: "The big brother.“

The socialite previously revealed she had always wanted a daughter named after the English capital.

Speaking on a ‘This is Paris’ podcast titled ‘This is… I’m Pregnant??’ before she had her son, she said: “One day I want to have a little girl, and I want to name her London. That’s always been my dream ever since I was a little girl, because I just love London and Paris together.

“For a boy, I want to name him after a city or a country or a state as well. I have a name, but I’m not going to say it yet – I want to keep it a surprise, and I don’t want anyone stealing my baby name for that one. I’ve said London for a long time so I can’t really hide that one now.”

And when she confirmed Phoenix's name, she admitted she had chosen a moniker that would complement London.

Speaking on her podcast, the 'Stars Are Blind' hitmaker revealed an excerpt from her upcoming memoir 'Paris', which read: "If all goes well, by the time you read this, Carter and I will have a baby boy. We plan to name him Phoenix, a name that I decided on years ago when I was searching cities, countries and states on a map looking for something to go with Paris and London.

"Phoenix has a few good pop culture reference points, but more importantly it's the bird that flames out and then rises from the ashes to fly again.

"I want my son to grow up knowing that disaster and triumph go around and come around throughout our lives. And that this should give us great hope for the future."