Serena Williams has given birth to a baby girl.

The 35-year-old tennis star and her fiancé, Reddit co-founder Alexis Ohanian, have reportedly welcomed a little girl into the world, weighing 6 pounds, 13 ounces.

According to reporter Chris Shepherd from , a source at St. Mary's Medical Center in West Palm Beach, Florida, confirmed the couple's happy news, with Chris taking to Twitter to reveal: 'Tennis star Serena Williams gives birth to a baby girl weighing 6 pounds, 13 ounces. Mom and baby doing well.'

Shortly after the news broke, congratulatory messages began pouring in for the couple on social media, with fans and friends alike sharing their joy at Serena and Alexis's happy news.

Beyonce, who gave birth to twins in July, was one of the first of Serena's high-profile friends to offer their well wishes, taking to Instagram to share a stunning image of the tennis star, taken from her recent Vogue shoot.

The popstar didn't caption the picture, instead choosing to overlay it with a simple, yet sweet message: 'Congratulations Serena!'

Serena's fellow tennis pro Rafael Nadal also shared his joy at the news on social media, writing on Twitter: 'Congrats Serena!!! So much joy for you!!!'

According to reports, the 23-time Grand Slam winner checked into the hospital on Wednesday, with an entire floor of the location being cleared in order to ensure the mother-to-be has the maximum amount of privacy possible.

Serena, who announced her surprise pregnancy with Alexis, 34, back in April, is reportedly due to give birth on Friday, after doctors made the decision to induce her on Thursday night. 

Local news outlet  reported on Friday morning that doctors have confirmed that Serena was admitted to the hospital on Wednesday, after the entire first floor of the location was shut down to all unauthorized personnel.

Currently, nobody without official security clearance, is able to access the area.

The couple revealed earlier this year that they had chosen to keep the sex of their child a secret until her birth, however the sporting star did reveal to Vogue that she believed she was having a daughter - a guess which happily became fact on Friday afternoon.

Alexis, however, was convinced that their baby will be a boy.

'Two weeks after we found out [I was pregnant], I played the Australian Open,' she recalled.

'I told Alexis it has to be a girl because there I was playing in 100-degree weather, and that baby never gave me any trouble. Ride or die. Women are tough that way.'

Daily Mail