The first term of the new school year is surely a time for hope and new beginnings.

There’s hope that the blazer will survive three days without getting lost. That we can get to midday without a mobile being confiscated. Hope, too, that my teenage daughter doesn’t hold the school’s record for rolling up the shortest skirt.

By the time you’ve hit half-term, you’re just longing for it all to be over.

As a mother of four, I’ve been slogging my way through the education system for 22 years now, enduring so many screaming rows in the car over everything from forgotten textbooks to exactly why their skin is that dreadful St Tropez-induced shade of orange, that I think my battle-weary brain has blanked out the trauma.

But, finally, the end was in touching distance. In September last year my youngest, 15-year-old Dolly, was due to embark on Year 11 at her private school in Surrey. Once the hell of this final GCSE year was over, I knew the Sixth Form college years would be infinitely less stressful.

So why, you might wonder, would I willingly prolong the agony – both mine and Dolly’s – by insisting that rather than entering Year 11, she instead do Year 10 all over again?

Before you ask, no, it wasn’t because she was failing at everything. On the contrary, she was on course to get good grades.

Many might therefore argue that choosing to go educationally backwards could only be a detrimental step. Yet, I’m convinced – and so is Dolly – that it was the best decision we’ve ever made.

Until the end of the 2023/4 school year, Dolly attended a Grade II-listed boarding establishment with such huge grounds there was one acre of land for every pupil. Even with a coveted music and drama scholarship, it cost us an eye-watering £24,000 a year.

Her older siblings also attended private school until they reached their A-levels, the logic being that if they hadn’t reaped the benefits of the £200,000-plus it had cost to get each of them to GCSEs then, frankly, there was no hope.

Plus, we would simply have run out of money. Forking out nearly £1 million to put four of them through the private sector has meant we’re almost certain to be living in a cardboard box under a bridge when we retire.

But back to Dolly. She had just one year to go and then two things happened. The first was Labour announcing 20 per cent VAT on private school fees. For some parents, this was a mere ripple. For us, it was a fast-approaching tsunami.

Second, Dolly was feeling increasingly unhappy. The school was over an hour from where we live in West Sussex, and the timetabled day began at 8.20am and finished at 5.30pm. She was regularly out of the house for 12 hours, and it had a detrimental effect on her school work because, once she did get back, she was too exhausted to do any homework.

She could have flexi-boarded a few nights a week but the full-time boarders were a cliquey bunch, mainly from overseas. She tried it for a year but felt homesick and lonely, so we went back to the draining commute.

Everybody knows that when a child is miserable, they stop learning. We were faced with shunting Dolly through another year, paying thousands to watch her wilt under the pressure – or moving her to a school nearer home at the most crucial time in her education.

I’d heard horror stories from mothers who had done this to their child between Year 10 and 11. Different examination boards, changing GCSE subjects at the last moment, repeating coursework. Well, obviously we weren’t going to do that.

But then, during the Easter holidays, I had a thought. Dolly is an end of August birthday, often closer in age to children in the year below. Why couldn’t we transfer her to our local state school and move her down a year – having her repeat Year 10? We’d swerve the VAT-induced fees increase, and give her a shot at better grades. Problem solved.

Or so I thought. My state school of choice in the next village had just received an outstanding Ofsted report. It consequently had a waiting list longer than A&E on a rowdy Friday night. And the education department at West Sussex County Council totally saw me coming.

After I optimistically applied for a place for the next school year that April, the conversation went something like this: ‘So, Mrs Sibary, having previously turned your nose up at sending your child to an amazing free school practically on your doorstep, you are now coming to us begging for a last-minute place because you’ve run out of money?’

Er, yes. ‘Well, sorry to burst your bubble . . .’

Not only that, but the state system rarely puts children back a year. In the private sector you can ask for what you like; you’re the client. When the Government is footing the bill, it is under no obligation to pay for an extra year of schooling if it doesn’t deem it wholly necessary.

Left lingering at eight down the waiting list, the odds were hugely against us, so I told Dolly the likelihood was she would have to stay where she was. But she was so unhappy she told me she’d rather do her GCSEs from home.

While you may think that falling behind her friends would be the source of further teenage angst, she didn’t see going down a year at a new school as detrimental or embarrassing – rather as saving her from another year of misery.

There were two other state schools in our area. But for the first one you had to be church-going to get in, which we aren’t, and the second – how shall I put this politely – was not an option I was prepared to consider.

Then, by some unbelievable miracle, a place suddenly became available at our chosen school in the week before the summer holidays, and an overjoyed Dolly was told she could repeat Year 10 come September.

We had a chat about what she was going to say to everyone as the new girl who had moved down and already done Of Mice And Men and most of the biology syllabus. But she was just honest, explaining she’d been unhappy at her previous school and wanted to be nearer home.

And, on the whole, the transition was smooth. There were some predictable side swipes about moving from a ‘posh’ school and the inevitable teenage posturing, but one of the advantages of now being the oldest in the year was that Dolly could handle herself. She wasn’t going to be derailed by a bit of bitchy banter.

The biggest plus, according to her, has been the standard of teaching at her new school – the one I’m not paying for – which she says is almost unrecognisably better.

‘Mum, the teachers here don’t faff around like they did at my old school,’ she told me in her first week. ‘We come into the classroom, get out our books and the lesson begins!’

I’m grateful, but it’s a bitter pill to swallow to think we might have wasted hundreds of thousands of pounds on buying her a ‘better education’.

She is learning more in a shorter day with a longer term. It appears to be a highly successful system. Obviously, the proof will be in the pudding, but she is on track now to get better GCSEs than she would have done had she stayed in the private sector.

Meanwhile, I can’t help feeling a bit like a villager in The Emperor’s New Clothes. It appears I’ve been duped for decades. Yes, there’s no denying the focus on manners a private school education brings. Not to mention incredible sports facilities and decent wine served at parents evenings. But, academically, it seems an outstanding state secondary can be just as good – if not better.

As for our decision to put Dolly down a year? Admittedly, I don’t think it would have worked if she’d been a September baby. The age gap would have just been too wide. But otherwise, any parent baulking at doing this or seeing it as a negative should reconsider. Some children just need extra time to reap the benefits of the school system.

I also believe she’ll be better prepared to cope with university.

We’ve got just one year left before she enters Sixth Form, but I sorely wish we had more. I wish I could turn the clock back and put my children through state education from the start. I don’t know what I was thinking.

What I do know is that if we had done, we’d be able to turn the heating on when we’re old – and, as she is now, Dolly would have been exactly where she needs to be.