This morning my eight-year-old daughter came downstairs with a face full of make up, writes Ellen Widdup.

It was badly applied and included bright red cheeks, blue eyelids, a splatter of glitter and a smear of sticky pink jelly across her mouth.

I am partly to blame for her fascination for lip gloss after filling her Christmas stocking with all my samples.

But the majority of the responsibility lies with a host of pre-teen girls she so desperately looks up to.

They include the lanky long-legged older sisters of friends, the gaggles of schoolgirls she sees hanging out in the park and the groups that congregate in coffee shops to share a single skinny latte and snigger over their phones.

Last weekend we went for lunch at a diner in town.

On the table next to us were two gawky-looking pre-pubescent boys, red-faced and awkward next to their glamorous companions - four incredibly self-assured young ladies who couldn’t have been older than 13.

They were flicking their manes of glossy hair while posing for a series of selfies with an obligatory pout.

I watched, mildly amused.

But my daughter was utterly transfixed.

For every shot they sucked in their cheeks and stuck out their lips.

Then they would skim through the images looking for the best before adding a soft-lit filter and sticking them up on an Instagram feed – no doubt accompanied by a selection of illiterate hashtags.

“They would look better if they smiled instead of pulling silly faces,” I whispered to my daughter, who frowned in response.

“I think they look beautiful,” she replied. “You are just too old to get it.”

And, while that well and truly have put me back in my place, she has got a point.

But then again, I’m not supposed to “get it”.

Teenagers have a duty to alarm, infuriate and irritate their parents.

To push the boundaries and make a statement. I certainly did.

At 13 I started rolling my school skirt up at the waistband to make it as short as possible.

At 14 I would wear heavy black kohl eyeliner – a ridiculous look with my fair hair and freckles.

At 15 I wore a Sex Pistols T-shirt to church.

Then at 16 I had my nose pierced. I couldn’t wait for the fireworks at home but was faintly horrified when my mother said she loved it and suggested that she might get one too.

Piercings, tattoos, badly applied make up and inappropriate clothing is par for the course for many teenage girls.

Complain if you will about the lash extensions, Ugg boots, crop tops, short shorts, improbable heels.

All a waste of breath.

Sure, we can provide a bit of tactful guidance but part of growing up is about rebelling from the norm and experimenting with the wild.

Teenagers use make up and clothes to show off their identity.

By and large, they don’t want to be clones of their parents.

Instead they join their peers in sporting dropped crotch jeans and traumatise mum and dad with slapped-on clown makeup and a riot of hair colours.

If they don’t, how will they ever learn what suits them, or have the hilariously embarrassing selfies to look back on?

Besides which, from what I remember, it’s hard enough being young without being on the receiving end of constant criticism from fraught, overly concerned parents.

It’s so unfair.

Nobody understands you. People have no idea tell you what to do all the time.

Everyone patronises you. You are oversensitive, easily hurt, and inexplicably angry.

Life is boring. Or confusing. Or overwhelming. Or lonely.

Neuroscience is wheeled out on occasion to explain teenage behaviour in reductive ways.

We have had plenty of reports describing how risk-taking is controlled by parts of the brain that do not mature until later.

And studies have shown that the frontal and parietal lobes responsible for planning and self-control - the bits that don’t envision the consequences of their actions - are not fully formed in teens.

This apparently explains why our teenagers behave as they do and why we, as parents, look upon said teenagers with a mixture of exasperation, rye amusement and, it must be said as well, a smidgeon of envy.

The latter because, for all the negatives of this highly emotional period of our lives, none of us are so removed from the experience that we cannnot recall a few of our Technicolour highs.

After all, the teen years are full of big dreams, dangerous risks, unquenchable passion and gripping drama.

No wonder it is the period of our lives which involves the most extraordinary self-expression.

So, as adults, we might not always agree with the way our teens look or the way they behave but I say ‘pick your battles’.

Simply demanding that they clean their faces, cover up and conform to your preferred norms will get you nowhere, will it?

Which is why, even at eight, I am giving my daughter the freedom to find out who she is.

If this involves a crazy face of powder and lipstick and blusher and pouting, then so be it.

Teenagers don’t do “appropriate” and nor should they.

That’s for later in life – when the rebellious rage has dimmed.

Then the tubes of sweet-scented lip gloss will be replaced with little pots of Chanel.

And the likes of Coast will exert a greater pull than Claire’s Accessories.

@EllenWiddup