As Tracy Beaker, Dani Harmer has played one of the most iconic roles in children's TV for nearly two decades.
CBBC says her most recent three-part series, My Mum Tracy Beaker, has been its most successful programme launch ever.
But Dani says abusive online comments she's received about her appearance has taken some of the shine off its success.
"It shouldn't affect me but I'm a human being," she tells Radio 1 Newsbeat.
Although she says the overwhelming majority of opinions have been positive, a small minority are "horrible" and are the ones she thinks about when she goes to bed.
"I am an actor and I'm used to criticism. But that doesn't mean a random person can sit behind their keyboard and let me know that I'm fat."
Dani was 13 when she debuted as Tracy Beaker in 2002, at a time when social media barely existed.
"I was so lucky because I don't know if my skin would have been thick enough to have dealt with it back then."
She's urging people to be kinder on social platforms and says it's taken her a long time to find her voice and "speak up things I don't agree with".
"Social media should be such a positive place but at the moment I don't want to even open my phone. I've just got such bad anxiety that someone's going to say something.
"Life is hard enough as it is. Let's spread some positivity and not make it harder for each other. We don't want a repeat of what happened to Caroline Flack. She was such a lovely woman."
She understands that sometimes people are "trying to get a rise" out of her but it's hard "not to respond back".
"I'm 32 now. I can't even imagine what younger people have to go through."
Although if we're talking about Tracy, you can imagine the two words she'd say to those people: "BOG OFF."
In the latest series, Tracy's 10-year-old daughter Jess deals with the arrival of her mum's new boyfriend Sean, played by Jordan Duvigneau.
Dani's now a parent herself and admits that although it completely changes you as a person you "really don't lose your true self".
"I knew I wanted to keep Tracy exactly how she was but I also wanted to show she had matured and was being less selfish.
"Since I've been doing this, it's always been nice to have a strong female character on kids' TV. She's bossy, sassy and knows exactly what she wants."
The fans also went into overdrive when she came face to face with her old nemesis from the foster home Justine Littlewood, played by Montanna Thompson.
The BBC says on iPlayer, My Mum Tracy Beaker was streamed 2.1m times in its first three days of availability (12-14 February).
"I never expected those numbers," says Dani.
"I've been so overwhelmed I can barely speak."