Yasmin Finney did not know what to expect. Hoping to break into acting, she had auditioned for two TV series - one of which had only a code name. Eventually she learnt that she had got both parts. One was Elle Argent in Heartstopper - but what about the other? "Then I found out what the show was and I was like, 'Oh my God, I've just been cast in Doctor Who!'"

The BBC is screening three Dr Who specials next month to mark the 60th anniversary of the series. Finney plays Rose, the daughter of Donna Noble, who was the Doctor's companion back in 2010.

Finney, who has just turned 20, first attracted attention through her TikTok videos about being a Black transgender teenager. She now has 1.7 million followers.

She was brought up in Manchester by her Jamaican mother. She has never met her part-Irish, part-Italian father and has had a difficult relationship with other family members. But, she says, "You have to forget all the bad stuff, because they're your blood. But be careful: I'm not saying you need your family, that's definitely not true. It's just a nice add-on."

Her childhood was a tough one. There was little money, and she and her mother and sister often found themselves in temporary accommodation. At school she was bullied "left, right and centre".

At college she studied performing arts, but was not optimistic about making it as an actress. Instead, she thought she would "just do TikTok for the rest of my life".

TikTok, though, was a mixed experience. On the one hand, "I had that platform and I could post what I wanted, and people loved how outrageous it was". On the other, "There was a lot of hate online, and there still is... It took a while for me to navigate that".

Due to the pandemic, she had to audition for Heartstopper on Zoom. Her performance won her a Children's and Family EmmyThe Emmy Awards are television industry awards. Award nomination. One critic described her as "Gen ZShort for Generation Z, meaning people born in the late 1990s and early 2000s.'s brightest new star".

"Being a trans woman is part of who I am, but it's not all that I am," she says. "I have much more to contribute than my identity. I think I'm excited to show people a different side of me. To this day, I'm still figuring myself out."

Yes: Without it Yasmin would never have found acceptance and broken through into acting. It gives you a chance to connect with people from all over the world who think the same way as you.  

No: It takes up a huge amount of time which would be far better spent doing something active, and is too often a vehicle for bullying, showing off and fake news. It only reinforces people's prejudices.

Or... It depends who is behind it. TikTok, Facebook and Instagram have all been criticised for not doing enough to combat bad behaviour online. Britain's new Online Safety Bill may help.