Paris Hilton's baby girl! Heiress tells fans she's 'thankful' for daughter London in surprise Instagram post... 11 months after secret arrival of son via surrogate

Paris Hilton made a surprise baby announcement on Thanksgiving, telling fans she is 'thankful' for her daughter London.

The star, 42, shared the happy news by posting a pink baby outfit with the name 'London' - thereby revealing the gender and name of her little one - though it's unclear if the baby has already arrived.

'Thankful for my baby girl,' the heiress wrote in the caption of the image. 

This will be her second child with husband Carter Reum. The pair welcomed son Phoenix via surrogate in January. 

DailyMail.com has reached out to representatives for Hilton for comment. 

While the news of her second child's arrival has come as quite the surprise, the name itself does not.

Hilton opened up in a live chat episode of her podcast on March 1 that she had picked out the name London if she ever had a daughter over 10 years ago.

'I'm really excited for Phoenix to have a baby sister one day—named London. It's my favorite city and I've always wanted to name my daughter London,' she said.

'I had actually picked that name for a long time now, probably over 10 years. I always wanted London. I love that name for my daughter,' she added.

The heiress named after the French capitol clearly wanted to keep the city-naming tradition alive with her kids, admitting Phoenix wasn't easy to come up with.

'It was hard to pick (Phoenix) because a lot of the cities that I like just wouldn't sound good as a name,' she said.

'Like Ibiza would be so weird as a kids' name, Vegas would be weird. It's difficult to find a cool name that's a city for a boy. Besides London, (because) that works for both,' she said.

While it still isn't known if London has actually arrived, or if Paris will have the child via surrogate like Phoenix, a sneak peek of her new reality show Paris in Love reveals that Paris and husband Carter Reum literally told no one about Phoenix, not even their own families.

The clip shows Carter driving with Paris in the passenger seat, telling her husband, 'If people found out, there would be paparazzi all over Cedar's (Sinai). I'm hoping and praying that no one at the hospital tells.'

'If anyone recognizes me, let's pretend that it's our nephew,' Paris says, as Carter jokes, 'Can't blow our cover now, we've done such a good job.'

Paris is then seen in a confessional in her walk-in closet stating, 'Literally no one knows,' about her baby.

'No one in this house knows. None of the people who work at my media company know. My friends don't know. My own family doesn't know,' she spilled.

Her husband Carter shared in confession, 'I don't think it ever hit me we weren't gonna tell anyone. That was really Paris.'

'My initial inclination was to tell my family and get everyone excited. Hers was to kind of hold the secret, but she's had to go through life having to protect herself, so I was gonna do everything I could to be a good teammate,' he said in the clip.

Paris added on her This Is Paris podcast, 'Not even my mom, my sisters, my best friend knew until he was over a week old.

'It was really nice to have that with Carter, be our own journey together. I just feel like my life has been so public, and I've never really had anything be just mine.

'So when we were talking about it, I really felt that I wanted this journey to be for us only. 

'Because we were so excited and wanted to tell our families, but we were just nervous because if you tell a person, then they tell someone, and all the sudden, it's in TMZ or Page Six, and I've had enough of my life like that.

'So Carter and I literally made a pact together that we would not tell anyone, and no one knew until just recently.' 

After Phoenix was born via surrogate in January, Hilton revealed in late February she underwent IVF treatments in an effort to have a daughter.

Paris told Glamour magazine: 'We’ve done it seven times… I have all boys. I have 20 boys. I just went through the process again a month ago, so I’m waiting for the results to see if there’s any girls.'

She also confessed that she had previously had her eggs frozen on the advice of her pal Kim Kardashian, and had been planning to have a child on her own before she and Carter met.