Ellen DeGeneres breakout star and YouTube sensation Sophia Grace Brownlee, 21, announces she is expecting second child

Sophia Grace Brownlee has announced she is expecting baby number two.

Brownlee, 21, revealed her pregnancy in a YouTube video posted to her account on Sunday.

Brownlee rocketed to fame when she became a viral sensation after appearing on the Ellen DeGeneres Show as an eight-year-old singer, performing a Nicki Minaj song alongside her five-year-old cousin Rosie McClelland, who is now 17. 

The YouTube sensation welcomed her first child, a son named River, last year.  

'So as you can see by the title of this video, I am expecting baby number two,' Sophia began. 'I'm so excited to be doing this video, I’ve been hiding this for a super long time. I have actually seen some of you guys guessed it in the comments and I really wanted to be like, "Yes, I am."'

'As a very paranoid, very anxious person, I always like to wait until I’m at least like around the 20-week mark,' she elaborated. 'And I almost am that now.

'So I thought it would be the perfect time to announce it,' she added.

'I am currently around 19ish weeks, almost 20 weeks. I've had both of my scans and everything's been fine so far,' she also said. 

'I'm actually finding out the gender today... and that video will be coming soon,' she also revealed.

'I'm only around 20 weeks right now but I do have a little bit of a bump already,' she said as she showed off her growing midsection. 

Brownlee also described how happy she was to give her son a big brother: 'Because they’re quite close in age, they can grow up together, and I just think that’s really sweet. I always wanted a sibling that was really close in age, and I didn’t have that, so I want to do that for River.'

She did not reveal the identity of her child's father but in a video uploaded earlier this month she confirmed she was still with her longtime boyfriend, who is the father of her son River. She has not revealed her boyfriend's identity.

'Yes, I'm still with River's dad. We have been together since I was 16,' she said in the video. 

British-born cousins Sophia Grace and Rosie first went viral more than a decade ago when their parents posted a video of them covering Nicki Minaj's hit song Super Bass.

The duo subsequently made numerous appearances on the Ellen DeGenerous Show, charming the powerful comedian with their adorable accents, precocious personalities and love of pink tutus.

The young girls instantly became a sensation and continued to be one of Ellen's favourite acts.

Ellen repeatedly brought Sophia Grace and Rosie back on her show, introducing the girls to their favourite celebrities and turning them into red carpet correspondents.

The adorable cousins were eventually given their own segment called Tea Time with Sophia Grace and Rosie where they interviewed everyone from Miley Cyrus to Hugh Grant.

Two picture books for children were constructed around the girls and they even received their own movie – Sophia Grace & Rosie's Royal Adventure.