I love being around my daughter, who is almost 13. I love dancing in the kitchen while I’m cooking, I love screeching like a castrato along to her Mika album, I love chatting to her amusing friendboys/girlfriends, I love watching television with her, I love gurning into her webcam when she’s online so she gets instant warning messages saying, “OMG Charlotte, turn off your webcam! Your mum! She’s scraping.” (Scraping means, in teen speak, barging into a place where you’re not wanted; OMG is of course an acronym for Oh my God). I just love all of it.

But my daughter doesn’t always love being around me and categorically loathes all the antics referred to above, which bring her out in goosebumps, with the possible exception of us watching specific, named TV programmes together (America’s Next Top Model, Desperate Housewives), which she will permit so long as I maintain reverential silence during the entire transmission.

If I sing, she turns up her iTunes very loud to drown out the aural torture. If I dance or so much as waggle my hips or click my fingers — let alone get vaguely jiggy to the beat — she has to leave my presence, shrieking: “I’m warning you. If you ever, ever do that in front of any of my friends, I swear. I. Will. Kill. You.”

If I wear my “embarrassing” fluffy fake fur to her school, if I use slang words such as “hot”, “buff”, “mank” or “booty”, if I try to talk to her about her webpage she will merely arch an eyebrow, look infinitely weary and say: “Face it, Mum, you’re sad.” (She’s too nice to say, “You’re old”, but I also have to face it. To a 12-year-old a woman of 41 is not merely old, she’s ancient.)

And I smile and cheer inwardly, because my daughter’s reaction to my efforts to pal up and groove on down (when I told her in a loving way once that I was her best friend, she told me simply: “No you’re not, you’re my mother”) is exactly right. There is nothing more embarrassing than a mother who doesn’t act her age, except — possibly — a white middle-aged male who insists on accompanying his son to a gangsta rap gig and giving a vigorous elbows-out display of daddy dancing in front of all his mates, perhaps wearing low-slung designer jeans and with his baseball cap the wrong way round.

So when I hear mothers saying they are best friends with their daughters (why is it that fathers never claim they are best friends with their sons?) my nostrils twitch suspiciously. Because I know how it works. I may want to be best friends with my daughter, but she shows not the slightest interest in being best friends with me, and very healthy that is too.

She is a girl, I am a woman. She is my daughter, I am her mother. She is a chick, I am . . . the hen. There is a natural order to these things, which is why the news that Charlotte Church is having a baby at 21 and the Duchess of York, 47, has yet again been pictured “romping” on a beach in Jamaica with the teenage Princesses Eugenie and Beatrice make me cringe, partly with anguished self-recognition.

But first the Church news, which was greeted with the creepy headline “Charlotte is expecting a little angel of her own”, as if the Welsh singer was not going to have a baby with her lunk of a rugby playing boyfriend, but about to amaze us all with the mythical feat of parthenogenesis.

As this headline reminds us, when we think of Church (not that I do, much) we do not think of her as ripe for motherhood, we think of the teenage “voice of an angel” who has sung for popes and presidents. And above all, we think of her as joined at the hip to her mother and former manager, the redoubtable Maria.

Sometimes you see a picture of Charlotte with her mum and you have to look for an extra second to work out who is Miss Church and who is Mrs Church. Equally, when it comes to the duchess and her daughters, it is not clear who is older and who is younger, who is in charge and who is dependent, who is the parent and who is the child.

It all seems to be a terrible muddle, as Fergie herself admitted when she revealed that she went out on the town with her own daughters, to whom she was so welded that her name for them was “the tripod”.

“It’s such fun because we go out on the pull together,” she said. “She [meaning Eugenie] longs for me to have a boyfriend and I long for her to have one. I say, ‘Look, what about him,’ and she says, ‘Oh Mum, no, we’re mates’.”

Now I hope and pray that my children would rather shoot me than allow me to go out on the pull with them, but as we have seen, my daughter will have none of this loopy co-dependent chumminess. But this Fergieish pattern of behaviour is increasingly common — and increasingly damaging, I would argue, especially to daughters.

In our mothers’ generation economic depression was normal, repressive conservatism was normal, nuclear families were normal, early marriage was normal. For our daughters’ generation, what is normal is economic recovery, political upheaval, varied and blended family life, delayed marriage and a high divorce rate.

So the current generation of parents is full of 1) ageing baby boomers and 2) single mothers, and both these sorts of parents are predisposed to treat themselves like the children they should themselves be preparing for adulthood. This explains the rash of neologisms, almost amounting to a new lexicon, of words such as “kidults”, “boomerang kids”, “youthhood”, “middlescence”, “adultescence” and “middle youth”, when we used to just have two serviceable terms: adult and child.

As Michael Bywater, the author of Big Babies — Or: Why Can’t We Just Grow Up? points out: “The baby boomers once thought that they — we — could have it all. Realising they could not have it all made them want it even more. Like greedy children, they learnt to manipulate, infantilise (“Daddy, bad daddy”) and be infantilised in turn (“Only ickle”). As age came on and the Stones became more tottering than Rolling, nothing changed; lacking any model of adulthood, the baby boomers, instead of really growing up, simply became bigger.”

With single mothers, as the duchess is, it is all too easy to see why rather than endowing their offspring with roots and wings, they lumber them with best friend status instead. For single parents their main emotional relationship is often with their children — whom they live for, through and with — and not an equal and independent adult partner.

Both are unhealthy, and this is why. If mothers go around with their daughters, scraping into their lives, claiming they are their best friends, it deprives their daughters of both a real best friend their own age and a proper mother — both at the same time. So . . . wrong (as my daughter would say).

rachel.johnson@sunday-times.co.uk

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