I sometimes feel a bit sorry for Amy Schumer. Her phenomenally successful career, which includes sellout arena tours, a bestselling book, a Hollywood career and, for many young women, rising feminist-icon status, makes it difficult, admittedly – but I do.

Why? Because simply by being a woman in the public eye, existing, and having the audacity to do so without the perfect size-zero proportions demanded of the women on our screens, she has been forced to become a spokeswoman on society’s body-image fixation.

The latest “controversy” is being cast as the lead in the upcoming Barbie movie (she is also, incidentally, working on the script, not that anyone seems interested in this). Apparently she doesn’t have the right figure to play Barbie. (Actually no actor does; a real woman with the conventional Barbie proportions would be unable to lift her head or stand). Having kept shtum during the casting process, Schumer obviously felt she needed to respond to the people criticising her body. “Is it fat-shaming if you know you’re not fat and have zero shame in your game? I don’t think so … When I look in the mirror I know who I am,” she said, continuing: “It’s that kind of response that lets you know something’s wrong with our culture and we all need to work together to change it.”

You might argue that Schumer would be better off ignoring the trolls and the misogynists. And were such proclamations about which female bodies are fit to enter our lines of vision limited to social media, I would probably say that she should do so. But this body fascism is our culture – it surrounds us, seeping into our minds from the pages of women’s magazines and the garishly coloured humiliation boxes that make up the sidebar of shame, criticism spieling like hateful streamers from the mouths of celebrated people, and our own peers, too.

Women will be aware how often we direct this at ourselves too; we have our own internal trolls. We learned the script from a very young age.

Which is why it’s important to think of the girls who see this happening every day, and – no matter how strong they are – absorb it. To have just one woman stand up and say, “I’m not having this” is a much-needed, powerful statement.

The girls are also the reason why Schumer is perfect for this role. I’ll admit that when I heard she was considering it, I was initially disappointed. That disappointment was nothing to do with her body, and everything to do with my feminist reservations about the Barbie brand (I had forgotten that, a year ago, Mattel diversified its range of dolls to include different body types and ethnicities, with great success).

The Barbie I grew up knowing was beautiful, saccharine – and dumb: “Math is hard”, declared her automated voice. But then I realised that Schumer was unlikely to kowtow to this vision of femininity, especially not if she is involved in the writing process. Instead, she will be cheeky, and sharp, and funny, and silly.

Think of any little girl you know. They love nothing more than a bit of silliness, and they don’t get it nearly enough. I am sure that they will love her when the film comes out. Maybe some boys will too.

The criticism of Schumer’s body is not coming from little girls, though. It is symptomatic of the predictable backlash that certain women in the public eye inevitably face. Now that the media machine has tired of Lena Dunham, the Schumer backlash has kicked into gear.

It’s not just about these women being successful and refusing to pipe down. Otherwise Tina Fey, Amy Poehler, Sarah Silverman, Ilana Glazer and Abbi Jacobson, and Jennifer Lawrence would all be facing similar tidal waves of hate (though it’s worth noting that men found another way to “humiliate” Lawrence; by revealing her naked body to the world). It is about their bodies not looking how women’s bodies are “supposed” to look, and – even worse – the fact that these women are unapologetic about that fact.

The only way to combat this body-shaming is to continue being unapologetic, which is tiring, sometimes soul-destroying work, and to champion better media diversity until it gets to the point where a woman’s words and talent count for more than the size of her backside. Schumer is doing her level best to help change the culture of body-shaming. It is, sadly, a task of Barbie dreamhouse-sized proportions.