Before I went to meet Helen Wright, headmistress and now author, I ask friends with teenage daughters to describe the issues that challenge them most.
"The usual," they all reply. One writes: "The same issues that we faced at their age but with more peer pressure, especially regarding beauty and sex."
Another emails: "Body image, anxiety and stress... The need to fit in/belong socially has resulted in the candle being well burned at both ends."
A third, who has three teenage girls texts me one word. "Heeeeeeeelp!!!"
Girls who are going through adolescence in the 21st Century are facing more – and more difficult – challenges than most of their mothers did.
Quite apart from the issues that we and our parents faced – alcohol, drugs, unwanted pregnancies – they have to deal with the march of the internet and social media, advances that have left them vulnerable to bullying.
But they are also bombarded with images of physical perfection – today's teenager may be faced with more of these images in a week than her grandmother was in a lifetime.
The pressure for excellence in other areas from parents and peers is greater than it used to be, too, and sexualisation is coming earlier and earlier. Even parents whose own adolescence was less than straightforward can feel lost in the maelstrom into which their daughters' teenage years are likely to descend.
But help has arrived in the form of a slim volume written by Helen Wright, a mother of three and respected headmistress of all-girls' schools, both in the UK and Australia.
Decoding Your 21st Century Daughter is a guide to understanding teenage girls and helping them to steer their way through the turbulent waters of adolescence. To parents torn between parenting fads of "helicopters" (constantly hovering) and "tigers" (hothousing children for academic success), her book will come as a welcome relief, a bit like picking up a Delia Smith cookbook after years of flirting with Nigella Lawson or Heston Blumenthal.
Its advice is practical, warm, friendly and hugely compassionate, as Helen is herself. As I enter the grounds of Ascham School, a grand, 127-year-old girls' school in the heart of Sydney, she is standing, beaming and waving, outside her office.
"You've brought the rain!" she exclaims happily as I get within hearing distance, as if that's a good thing on this winter's day.
Throughout her 20-year teaching career – of which she has spent 13 as a headmistress, most recently at St Mary's Calne in Wiltshire before her move to Sydney in January – Wright has spent many thousands of hours with teenage girls and their anxious parents, and become an expert on the reasons behind their behaviour and the issues that they face.
Parents speak of her in glowing terms. One of the mothers I contacted texted back: "My friend enrolled her daughter at Ascham because she'd been told the head is more interested in the whole child rather than just academic results."
Wright's ethos is deceptively simple: growing teenage girls into confident, independent, secure adults. It sounds an obvious aim – after all, isn't that what all parents want? But she points out, wisely, that it isn't as simple as all that because adolescence isn't a time of linear growth.
She compares the turbulence of the teenage years with childbirth, suggesting that this period should be thought of as giving birth to an adult because of the dramatic changes an adolescent girl goes through as her body and brain are readied for adulthood.
"So many parents are caught by surprise that this is not a linear process," she says, as we sit in her study overlooking a giant fig tree. "You want your baby to grow up, become more and more aware of the world, more and more mature, but you shy away from realising that this is a revolution. There's a lot of turbulence in these years and it can be confronting for parents. It's scary."
She says that parents come to her with the "same questions and the same fears" about their daughters. "They will say 'She's not feeling good enough about herself,' or 'She can't communicate'. They will bring up the range of typical teenage issues – bullying, drinking, partying – or they'll say 'She seems to be unhappy'."
They also come to her with "the same sense of being alone", and this is why she wrote her book, to let parents know they are all in this together.
"We have a collective responsibility for our children and we should share our experience and understanding," she says. I often have parents coming to me saying 'I have failed.' But they haven't failed. It's unfair to blame the parent when something goes wrong. How can you be expected to know everything?"
Her advice to parents is laid out in simple headlines.
Listen to your daughter but never try to be her friend; give her boundaries but let her take risks inside those boundaries; let her fail in order to grow enough to be a success. Never, ever, let her have any device that connects to the internet in her room. And remember: the slamming of doors and the "I hate you" moments will pass. Eventually.
I mention helicopter parents and tiger mothers – after all, it was Amy Chua, the tiger mother of all tiger mothers, who first declared: "I am not my daughters' friend. I am their parent," a tenet that is at the heart of Wright's philosophy. She gazes heavenward when I bring this up.
"It's really not that simple," she says before, very diplomatically, dismissing both forms of hyper-parenting as restrictive and ultimately damaging. As a mother of two girls and a boy aged three, six and nine, she refuses to criticise parents per se, coming back repeatedly to the fact that parenting is a hard job and parents should not be blamed when things go wrong.
But, she says, parents can "over-schedule" a child's life. "Children need space to become independent. As a parent you may feel that if you don't push your children they will never make the most of their life. But if you over-schedule their time you will end up with a nervous and dependent child.
"The best resource a child has is her mind. But they also need time and space to do nothing – to just think and grow."
On the other hand, she says, you can't ever be your daughter's friend.
"You can love her more than anything else in the world. But it's not painted pretty pink."
Wright agrees that children need boundaries and structures to feel secure and to have something to push against. But within those boundaries they also need to be able to take some risk, to develop resilience. Let them fall out of the tree? I suggest. There is a long pause. "Well . . . maybe the bottom branch," she accedes, finally. And as long as you're close enough to catch them.
One of the issues that most concerns her is self-esteem and the problems to which it can give rise, particularly the lengths girls go to for physical perfection. She is careful not to focus on her pupils but says that eating disorders are the most common problem she comes across as she describes how skilful girls are at hiding anorexia or bulimia.
She mentions Georgia Willson-Pemberton, an accomplished skier, who died in December last year after taking an overdose of laxatives. She had been a pupil at one of Wright's schools some years before anorexia took hold.
"She was determined and ambitious," Wright remembers. "But she had a lot of self doubt as do a lot of achievers.
"There are greater pressures on girls today than there have ever been. The celebrity culture has changed ideas of what it is to lead a perfect life and people feel that if they're not perfect they must have failed."
Her answer to eating disorders, as it is to bullying and self harm, is to build girls' self-esteem. "At my school we say you can do something about this. Take charge, be the best you can be," she says.
She makes it sound deceptively easy, and some parents reading her book could think that she was speaking to a privileged elite – especially when she advises recruiting the wider family of cousins, aunts and godmothers as mentors.
But not every parent has the good fortune to be surrounded by aunts and godmothers to whom they can turn, and not every parent can afford a school such as Ascham.
"I know," she says, "and that's why I believe in a collective responsibility. Teachers have it too. We're not responsible only for the pupils at our school."
She admits, too, that just because she's full of good advice does not mean that her own children are always angels.
"One of my department heads did ask me recently 'Do your children do everything you tell them to?' I said 'Of course not!'," – the only slip into personal anecdote she allows herself.
Do they slam doors and tell her they hate her? "I have a six-year-old girl so yes, we have had the slammed doors."
And the "I hate you?" She looks momentarily stricken. "Oh please don't write that my daughter says 'I hate you'. She would never forgive me."
It's a hard job. Parents shouldn't be blamed when it goes wrong.