Apparently there is a way to behave if you have been accused of, served time for and then been acquitted of murder. Things you can do: be silent. Things you cannot do: smile, be odd, talk about your experience, or turn it into a debut standup hour at the Edinburgh Fringe. That last one is a bit weird, yes. But it’s a weirdness that Amanda Knox, the woman acquitted of killing her flatmate Meredith Kercher in Italy in 2007, now embraces.

Everyone at the Fringe is aware of Cartwheel, named for the photograph that made it look like Knox was doing a cartwheel in police custody (“It was actually the splits”). The outrage started before the festival began, but despite more than 40,000 people signing a petition to call for her show to be cancelled, Knox has defiantly opened it to the public and the critics. Really though, very few people I’ve spoken to have actually seen the show, and fewer still are particularly bothered. As for the critics, reviews have been largely negative – but they are all by comedy critics, judging it as a comedy show. So what is it actually like to sit in a dark corner of a student union and see the face that sold a thousand tabloids? Mostly just very sad.

“My life is so weird”, Knox says in the opening moments, surrounded by the clutter of young kids. The show is set in her daughter’s bedroom, and sees her navigate how she will one day explain her tumultuous life story to her now four-year-old. Knox doesn’t shy away from the reason we’re all here. Her guilt, she puts it, is in being “deeply unsettling to the general public”. And it’s true: she has an ineradicable awkwardness. There are plenty of gags (a recurring joke about anal sex is probably the best one) but their impact is weakened by her slow, over-engineered delivery.

Even if she did speed up, it may not elicit more laughter because there is a palpable sense, in the nervous pre-show tension, that this is not an audience who has come to see stand-up. They’ve come for a freak show. As Knox continues, there are little pockets of people who offer generous laughter. The rest remain stony and staring. And those out to be disgusted may well find what they’re looking for. Some jokes lean into the darkness. She recalls how in a playground, seeing the prison-like metal bars of the climbing frames, her daughter wanted to play “mum goes to Italy”.

Vexing people most is the question of whether she talks about Kercher. She does. Knox reflects sincerely on Kercher’s kindness, and the cruel injustice of her death. Several reviews mention the comments by Kercher’s sister that the show risked “normalising violence against women by making light of such a harrowing event”, and note that that is the complete opposite of the show’s message. The fact that people assumed Knox would joke about murder makes its own point about how she is perceived, and how that perception has been shaped by a media which acts as its own justice system.

Soon the gags fade anyway, and Cartwheel becomes far cleverer than it is funny. It’s increasingly clear this is a category error – the same issue that plagued Knox. This show isn’t comedy, nor theatre, nor any of the other boxes you tick when registering in the Fringe programme. No one knows what to make of Knox, so they just tick the box “weird”.

And why should she not be? Why have we all claimed the right to police this woman’s behaviour? And how has nothing changed since 2007? Often, she interacts with the recorded voice of her daughter and worries about the world she’s growing up in. “I love that my daughter is fearless and friendly because that used to be me. I just know that someone someday is going to hurt my daughter, and then you’re going to ask what she did to deserve it,” she says.

For all its attempts at comedy, it’s that underlying sadness that keeps coming through. Despite the opprobrium and all the scrutiny, Knox says solemnly, “it’s not lost on me that I’m the lucky one.”

At the end, a few people rise to their feet. Some slip out hurriedly. One woman scoffs to her husband at Knox’s brazenness. Others chat excitedly about her bravery. Who knew: several things can be true. She has the right to perform a show about her life at the Edinburgh Fringe, and people have the right to be mad about it. She can write a clever and complex show, and it can be not very funny. In the end, she accepts her own strangeness. It doesn’t make her guilty, she points out. Nor does it make for a very good hour of stand-up.

‘Amanda Knox: Cartwheel’ is at the Gilded Balloon until 17 August