"It was important for me to show a different side to her, the much softer side to the persona," she says. "Amy hid behind her beehive hair in public because it made her feel more comfortable. She could use it as a prop, but it wasn't the real her. She was a very complex person, and deliberately so."
Winehouse says her decision to write the book - charting Amy's life from the day of her birth at Chase Farm Hospital in north London to the very end - was not one she took lightly. She first considered the idea in 2007, but was then warned off it by her daughter, who told her: "I don't want people to know who I am."
Now the book serves as both a handy resource for others with drug-addicted friends and family, as well as a deeply personal memento for the writer. "The condition that I have affects memory," she says. "I thought I had to do it while I could still remember all my stories about her. It felt good to relive them - a therapeutic experience. For me, it is a very personal thing. It is not about a famous person. It is about a real person. I wanted to show that these issues can affect anyone.
"I worry about the day when Amy stops being alive in my head and my heart," she adds. Not the performer whose bleary-eyed images were emblazoned across the world's tabloids in her final years, but the little girl who attended Yavneh nursery at Cockfosters and North Southgate Synagogue and portrayed Rizzo with impressive accuracy in an Osidge Primary School production of Grease.
The book is certainly insightful, offering rare glimpses behind the maelstrom of Amy's public life. One revelation is the crippling pressure the singer felt to surmount the success of her second album Back to Black, which went eight-times platinum.
Winehouse herself learned a lot about her daughter by "asking friends and family to recall their stories and find old photos. It was painful for me and for a lot of people. There were a lot of tears. But then there was also a lot of laughter."
One anecdote was of an eight-year-old Amy convincing her friend, Michael - the son of Winehouse's now husband, Richard - to race their bicycles downhill "with their trousers and pants around their knees and their bums in the air". When told off by a stunned elderly man, Amy responded with a V-sign.
"I couldn't believe that story when Michael told me," Winehouse laughs. "But then I'm sure they got up to far worse. The happiest part of writing this book for me was recalling her childhood. My coping tool is to find the humour in these things."
Winehouse - who became a grandmother for the first time in the week of the book's publication - says its completion brought a sense of closure, after a year of "sleepless nights" as she relived the highs and lows of Amy's life.
She is now focused on the future and ensuring that some good comes from tragedy through the Amy Winehouse Foundation, which she runs with her ex-husband, Mitch. All author proceeds will be donated to the charity, which works in the UK and the US to educate about drugs and treat addiction, and also to help nurture talent in the young and disadvantaged.
"We send reformed alcoholics and drug addicts into more than 200 schools across the country who tell it like it is. It is important to get to children at a young age because there is still not enough understanding or awareness. It's not about lecturing them, but giving them the honest facts.
"It also helps the recovering addicts. It puts them back in the system. By employing them, we are helping their recovery."
Among the foundation's diverse projects, it feeds more than 60 homeless children in central London every night, runs music therapy at the Haven House Children's Hospice in Woodford Green, Essex, and finances gifted, underprivileged children at the Brooklyn Music Conservatory in New York. It has also made a sizeable donation to Norwood, a poignant contribution for Winehouse, whose father was a Norwood orphan.
"To be able to link Amy's name to something so important is very satisfying," Winehouse reflects. "We knew something positive had to come from her passing."
Later this month, she and her husband will fly to St Lucia, the Caribbean island that became Amy's refuge in the last few years of her life, to present a cheque to the governor-general and prime minister. The money will be used to help children from impoverished backgrounds. She says the trip will be an "emotional experience", given that she last went to the island in 2009 to visit her daughter.
"Amy was so happy there," she recalls. "She was comfortable and free to run around and be herself, without having to deal with reporters. She didn't have to be Amy Winehouse any more." A week ago, she also attended the unveiling of a life-size bronze statue of Amy in Camden.
Her greatest hope is that the memoir will "set the record straight once and for all". To this end, she is at pains to stress that Amy had stopped using heroin by 2011 and had "turned a corner". It was alcohol that had caused her death. Beyond that, she wants to shed light on a complex, extraordinary talent. "I look at photos of her as a child and can't quite believe it," she says. "She was just my little girl, who I used to tell to shut up when she wouldn't stop singing."
