Every day after school, my 13-year-old daughter Bella tells me about her day. I did the same when I was her age. I recall chatting with my mum about the latest house netball scores, my test marks and who I ate my lunch with. When Bella relays the latest events, with dizzying stories of gender fluidity and sexual politics, it’s clear how much times have changed.

There’s the on-going saga of Bella’s friend Jessica, who came out last year after she started dating Alexandra in another Year 9 class.

Only Alexandra has since decided she’s now transgender and is living as a boy called Alex — who must only be referred to as ‘he’ — despite being a pupil at an all-girls school.

Bella, 13, appears to be constantly concerned that she’s regarded as boring for not being transgender or gay, and is anxious not to be frozen out by the cooler clique

There were huge dramas when another classmate, Rebecca, confessed to Laura, who is in her maths set, that she was sexually attracted to her.

Laura, who used to present as a boy, angrily rejected her, saying she had jumped to the wrong conclusions, leaving Rebecca in tears. However, Laura has since decided she is gay after all, and the pair are now dating.

As someone who was still working out who I was at Bella’s age, it all sounds exhausting — and yet another pressure on girls’ already fraught friendships.

Over the past year, Bella has totted it up and she and her friends estimate that around 12 per cent — one in eight — of her year group have already come out as gay, bisexual or transgender. Other parents I talk to at similar girls selective schools near us in the Home Counties cite similar percentages.

And it’s not just single-sex schools. In council figures released last November, Dorothy Stringer, a High School in Brighton, was revealed to have 40 children who didn’t identify with the sex they were at birth, with another 36 out of 1,600 children saying they were gender fluid.

Let me say now that if Bella came to me, after gaining some experience of the wider world, and told me she is sexually attracted to women, I would accept her choice happily and without question. Even so, I am not the only parent concerned that so many youngsters are coming out at such an early age.

According to the Government’s latest Sexual Identity Census figures — which are gathered anonymously — 1.6 per cent of adult women in the UK identify as lesbian, gay or bisexual.

Although it is not tracked, it is estimated that the number of transgender people lies somewhere between 0.2 per cent and 1 per cent.

But there’s a big gap between these official figures and what we are seeing in our schools, particularly among girls who studies show are more malleable.

It must be terrible to be trapped in a body which you genuinely feel has never belonged to you, says Suzanne Glover. But schools and parents also need to make sure that they don’t forget to tell our daughters there’s nothing wrong with sticking with the gender they were born with

Bella has had precious little information in her PSHE lessons on how to have a heterosexual relationship, yet at the start of this term she was given a seminar on gender and sexual preference led by five of the school’s transsexual, non-binary (not identifying as male or female) and gay sixth-formers.

Bella described walking into the hall and being shown a powerpoint presentation on the meaning of a selection of words, ranging from ‘transgender’ to ‘asexual’.

One word whose meaning Bella did not yet know the meaning of was ‘cisgender.’ The word, which is being heard more and more, is defined as ‘people whose gender identity matches the sex that they were assigned at birth’.

In other words, Bella has been told she now has a label for being born a girl and wanting to stay one. Baffled, she told me after school: ‘I am a girl. I like being a girl. Until now, it didn’t occur to me that I needed to justify it.’

After this word definition game, the assembled year group of 250 pupils were shown a video called: ‘Who Am I?’ Finally, the class was asked for a show of hands as to whether they had found the talk useful and enjoyable.

Bella told me: ‘I wasn’t sure about it. But I didn’t dare not put my hand up in case some of the other girls called me transphobic.’

Since the seminar, she now assiduously does her best to avoid the subject of gender and sexuality altogether at school. She has learned her lesson from the experience of other classmates and has witnessed girls, who have dared to question this massive shift, being verbally confronted by others who have come out or who are in the social clique who have.

Bella has learned to choose her pronouns carefully after innocently forgetting to use ‘he’ or ‘they’ instead of ‘she’ when talking about other transgender or non-binary pupils.

Anyone who slips, she says, gets snapped at by the pupils who pride themselves on being more ‘woke’ and enlightened.

Of course, Bella’s experiences don’t compare at all to the trials of young people who have felt trapped in the wrong body from a young age.

Equality campaigning group Stonewall claims that 64 per cent of transgender pupils have been subject to bullying and that almost half of trans people in Britain have attempted suicide, while 55 per cent will also be diagnosed with depression at some point.

There is, however, other research has also called into question what is really going on when young children want to change gender in large numbers.

In the UK, figures for the number of children who feel they are living in the wrong body and need to transition to the opposite sex continues to soar year on year.

One 13-year-old girl named Macie was told it looked like she and her friend were 'dating' because they’d held hands while running for a bus

Official figures from the Gender Identity Development Service at the Tavistock Centre in London show that more than 2,500 children were referred to them in 2017 to 18, which was a 25 per cent increase from the previous year.

According to a study published in scientific journal PLOS One last August, based on interviews with more than 250 parents of transgender teens, girls are more likely to experience ‘rapid onset gender dysphoria’ in which they suddenly identify as another gender after or during puberty — even though they never showed any previous signs of wanting to have a different gender.

Public health researcher Lisa Littman, of Brown University in the U.S., found that ‘social contagion’ might be a factor, while it was also noted that girls were more likely to have rapid onset gender dysphoria if they knew someone else who did.

When they came out as transgender, parents also said they noticed their children became more popular, gained more social media followers and were praised more. One parent reported: ‘Being trans is a gold star in the eyes of other teens.’

The flipside however is that ‘cisgender’ has become a term of abuse against straight teens.

Parents told the study how their trans children derided straight children, whom they viewed as ‘dumb and boring’, and were ‘disparaging’ about ‘heterosexuality, marriage and nuclear families’. Bella says she knows the feeling: ‘When I talk about liking boys to some girls in my year I am treated as if I am stupid and I don’t get it.

‘It’s like if you are straight and like the opposite sex, you can’t be a deep or evolved person.’

Yet, all our girls are finding their way — and belong to a generation in the midst of a mental health crisis, not just those who have gender or sexual identity issues.

As a parent it’s horrifying to know that 22 per cent of all 14-year-old girls now self-harm either by deliberately hurting themselves physically or through drug or alcohol abuse, according to the latest research by The Children’s Society.

On top of concerns about body image, measuring up on social media and the drive for exam results, this push to encourage children to question who they are at such an early age feels like just one more layer of pressure.

Children’s education consultant Nicky Hutchinson, co-author of the book Body Image In The Primary School, applauds the bravery of those sixth-formers conducting the seminar at Bella’s school, but she suggests it would have been helpful for teachers to add more context. She says: ‘Of course we must totally respect children who really know they are gay or transgender at the age of 13.

‘But there are an awful lot of children who are also uncertain at the same age, feeling they have to identify themselves by saying which camp they belong to. There’s a possibility that because some girls of this age think: “Oh I quite like that older girl” — as has always happened — or they are not yet interested in boys, they are rushing to categorise themselves or put themselves in a box. It’s as if we’ve forgotten that children go through phases.’

There’s also the devastating effect this is having on girls’ friendships. In terms of child development, having a close best friend has been a way of practising one-on-one adult relationships.

A thoroughly confused Bella wonders whether some of her classmates don’t just like her. She has to consider whether they fancy her, too. As a mother, I chose to send her to a single-sex school so she didn’t have to be saddled with these sorts of concerns.

Indeed, Bella showed me a text exchange in which a female friend had asked her if she had ever kissed anyone.

When Bella said no, she replied: ‘Want to try it with me?’

Because Bella and her own best friend are inseparable, Bella said she has also had to counter rumours they are gay — not that she has anything against being gay, she just isn’t.

My daughter believes that there’s definitely an element of the gender and sexual fluidity movement at her school that is for show. ‘The gay couples in my year don’t even seem to talk much at school,’ she tells me.

‘They mainly have their relationships on social media. They seem to like very intense relationships — with a lot of drama and breaking up and getting back to together — and they sometimes post pictures of them kissing.’

Another mother told me of similar scenarios at her own 13-year-old daughter’s school: ‘My daughter Macie’s school pushes a very sexualised agenda, and this seems to result in very young girls — age 11 to 13 — seeing the world, including female friendships, in a sexual way.

At Bella's school, the assembled year group of 250 pupils were given a lesson on gender and sexual identity issues and afterwards asked for a show of hands as to whether they had found the talk useful and enjoyable. Bella said: ‘I wasn’t sure about it. But I didn’t dare not put my hand up in case some of the other girls called me transphobic'

‘One girl said she thought Macie and her friend were “dating” because they’d held hands while running for a bus. Although pressure groups which push this agenda say parents are part of the problem and denying their children a chance to be themselves, I say they are just children, and people change a great deal between childhood and adulthood.’

But perhaps we also need to dig a bit deeper to look for other reasons girls are turning to each other for romantic relationships?

Maybe in a world where there is so much talk of misogyny — and in which some boys, having been influenced by porn, see girls as sex objects to do with what they like — an understanding female friend does feel like the safest romantic option?

So where are the current gender fluid policies in schools taking us?

By doing the highly commendable thing of trying to stop the small number of transgender pupils being bullied, are the rest of the class suffering?

Certainly Bella appears to be constantly concerned that she’s regarded as boring, and is anxious not to be frozen out by the cooler clique.

Of course, it must be terrible to be trapped in a body which you genuinely feel has never belonged to you. But schools and parents also need to make sure that they don’t forget to tell our daughters there’s nothing wrong with sticking with the gender they were born with — and that they can decide on their sexuality when they feel ready. Not when others tell them they are.