In the middle of the new book Amy Winehouse: In Her Words, there is a list of ambitions, penned when the late singer was a 16-year-old student at The Brit School. Some of them are standard teenage dreams: she wants to own a house in South Beach, Miami, and “300 pairs of shoes”; she wants fabulous hair – and her designs on a then-famous pop star are expressed in very forthright terms indeed. She seems more interested in becoming an actor than a musician – she wants to work with Michael Madsen and Steve Buscemi and “do a movie where I look ugly” – although she does express a desire to collaborate with Missy Elliott and producer Timbaland. Perhaps the most striking entry is No 12: “To have people look up to me.”

She certainly achieved that: 12 years after her death, Winehouse is still, by consent, the most influential British pop artist of the 21st century, revered by Lana Del Rey, Sam Smith, Lady Gaga and Bruno Mars, credited by Adele with “paving the way for artists like me”. We are still surrounded by echoes of her music: whenever you hear a bluntly confessional female singer-songwriter, or a retro-soul affectation in an arrangement, or a pop singer with a slurred, prematurely aged vocal style – and you hear those things all the time in 2023 – it’s more than likely Back to Black, her 2006 album, is somewhere in their musical DNA.

It’s a legacy that rests on very little music. You can listen to everything Winehouse released in her lifetime in under two hours, and the music that really matters – Back to Black and a handful of cover versions – in half that time. Since her death, there has been some revisionism about the quality of her debut album, 2003’s Frank, but if that was the only thing she had released, it’s unlikely anyone would be talking about her in 2023.

The brevity of her recording career feels as much part of the continuing fascination with Winehouse as the chaos and tragedy of her personal life. Within her scant oeuvre, Back to Black feels like an unprecedented bolt out of the blue, exactly where it came from faintly mysterious. One minute, Winehouse appeared to be part of a wave of female artists making music that was a little bit jazzy, a little influenced by soul, and which borrowed from 70s singer-songwriters – easy to lump in with Norah Jones, Corinne Bailey Rae or even Katie Melua; the next, she’d suddenly made one of the most revered and influential albums of its era.

Back to Black also presents a problem for those curating her legacy. Her estate and record label managed to cobble together a solitary album of outtakes, 2011’s Lioness: Hidden Treasures, but even that was evidently a struggle, involving overdubbing unfinished songs and demos. With no more music to feed it, the public appetite has to be satiated with other things.

Within her scant oeuvre, Back to Black feels like an unprecedented bolt out of the blue, exactly where it came from faintly mysterious.

Amy Winehouse: In Her Words speaks to both those factors. It’s a new, officially approved “product”, complete with text written by her family. If it can’t fully explain the lightning-in-a-bottle quality of the songs on Back to Black, it attempts to illuminate her career via personal photographs and handwritten ephemera. You can’t fault their thoroughness in raiding the photo albums and scrapbooks – there is everything from schoolwork to song lyrics, letters and diary entries – but it occasionally makes for a faintly discomfiting read, particularly given that Winehouse struggled with intrusion in her later years: the introduction rightly admonishes the paparazzi and tabloid press who camped outside her door for “robbing Amy of any privacy she might have wished for”.

It’s hard not to wonder who in their right mind would want their teenage diaries and to-do lists posthumously published, even in a book that offers a moderately sanitized version of her story. There are references to Winehouse’s “addictions”, while a number of handwritten notes and diary entries about dieting point to her issues with food – after her death, her brother Alex said that bulimia had fatally weakened her. But her ex-husband Blake Fielder-Civil’s name is never mentioned, only “an ill-fated-relationship”.

The photographs tactfully avoid her decline, too: a court drawing from one of her numerous assault charges aside, they jump from Winehouse in her element onstage to a selection of commemorative murals and tributes. Despite the fact that Winehouse’s name is a byword for the failure of the music industry to protect vulnerable artists, there is no apportioning of blame over her death.

Instead, there is a suggestion that she was possessed of a baffling, impetuous, self-destructive streak from the off: “We can’t say we understand her either,” offer the family in the introduction. Often the suggestion comes from Winehouse herself, abundantly aware that she’s a bit of handful: “The nutter of the class,” as one diary entry puts it, fond of “being loud and mouthing off to people… it’s the way I am.” The head teacher’s comments at the end of one school report say only “what a pity!”

You get the feeling she was about to be expelled from secondary school when she transferred to Sylvia Young Theatre School. But, as she puts it, she “quickly got into the wrong crowd” there, too. Her plans for setting up home on her own also give you pause. “Stuff I’m gonna keep in the fridge constantly: 1 Vodka. 2 Kahlúa. 3 Baileys. 4 Beer. 5 Babycham.” And so it proves: by the time of Back to Black’s recording, her to-do list opens with standard stuff about picking up food from M&S and meeting friends for dinner – then concludes with “go out and get fucked”.

“We can’t say we understand her either,” offer the Winehouse family in the introduction.

Not every unpublished lyric here gives an insight into her creativity. “Hello spider, it’s you again, I’m sorry I washed you down the drain,” opens one song; a list of potential topics for songs includes the promising line “you’re just one step away from being what I am” and the understandably abandoned “you ate all the nuts in the pub”. Nevertheless, she seems to have tended to both romantic despair and frank self-assessment long before Fielder-Civil hove balefully into view: one lyric depicts her “drained, sick and full of shit that I call poetry”, a line that could have featured on Back to Black.

For someone who gave every impression of living a spectacularly chaotic life – “Amy Winehouse and pathos are flatmates, and you should see the kitchen,” as the late Clive James memorably put it – she also seems to have been an unexpected stickler for detail. The image that became iconic (so iconic that, as one meme proved, you could draw a beehive and thick eye makeup on a £10 note and make Queen Elizabeth II look exactly like Winehouse) might have looked like it involved wearing whatever she woke up in, but it turns out to have been carefully crafted: Winehouse literally sketched out how she wanted to look and made lists of potential outfits.

You could spin the story told in Amy Winehouse: In Her Words as something more than just a tragic waste, a cautionary tale about what happens when the duty of care the music industry has toward an artist with mental-health problems is found lacking. After all, by the time she died, Winehouse had achieved pretty much everything her younger self wanted to achieve as musician. She was famous, successful and respected, not just by her peers, but by the kind of artists who inspired her in the first place: Missy Elliott and Timbaland were desperate to work with her; Tony Bennett compared her to Dinah Washington and Billie Holiday, possessed of “a spirit you’re either born with or you’re not”.

She wanted big hair and she got that, too. But it’s hard to see it as a saga of dreams fulfilled. For all the heartstring-tugging qualities of seeing her childhood photos and her primary school drawings, the saddest thing here might be a quote from Winehouse after she became famous. She isn’t “satisfied with one level of musicianship”, she says, before optimistically adding: “I’ve got all the time in the world to make that happen. That’s what’s so exciting: I’ve got years to do music.”

Alexis Petridis is The Guardian’s head rock-and-pop critic