A DECADE ago, when my twin sons were eight, I was chatting to a woman at a children’s party. Her own kids weren't there; it transpired that they were in their late teens and on the verge of flying the nest. "That’ll be so hard for you," I said.

She gave me a bemused look. "You really think so? God, no. Their music blaring, their friends lying about drinking all our drink, eating all our food… "She shuddered and gulped her wine. "I can’t wait for them to leave," she added.

I was shocked by what I perceived as heartlessness. Sure, many a day with my three children had reduced me to fantasising about driving away in a cloud of dust with my own music blaring; any parent – unless they’re the eerily ever-patient type – knows that the early years can be immensely trying. Yet to rejoice in them leaving home? I didn’t get it. As an utter wuss where my kids are concerned – the first to cry at school concerts, forever dabbing my eyes with a sodden tissue – I imagined I’d be weeping inconsolably in a puddle of gin.

Yet that hasn’t happened. While I sensed a tug of sadness as my sons packed up their possessions in preparation for university a few weeks ago, it would have seemed churlish to shuffle around feeling sorry for myself. They were thrilled to be leaving – more than ready and capable of looking after themselves. I was delighted for them. Even at 50 I can vividly remember leaving my family home in Irvine, at age 17, and setting off to a bedsit in Dundee to embark on a new, independent stage of life.

In fact, I am not sure 18-year-olds and their gnarly parents are designed to live together under one roof. Never mind us, craving a bit of peace, and for the washing machine not to be churning three times a day; how must it have been for them, being ticked off for leaving the table strewn with toast crusts when they were of legal age to marry and vote?

Certain friends have found this stage difficult, with one admitting she is still "bereft" at the departure of her daughter, one year on. Another woman I know – a single mother in her mid-50s – took the step of moving to the city where her 19-year-old daughter was studying art. While it took me a couple of weeks to adapt – I kept buying too much bread, which went mouldy – it felt right and necessary to let them go.

The fact that Jimmy, my husband, and I have been immensely busy has helped. Rather than staying in the family home in Biggar, South Lanarkshire, where we had raised our kids, we took the decision to sell our house, filling the biggest skip available with broken buggies, travel cots and numerous wrecked tents. We foisted unwanted furniture on friends, jammed the remainder into an immensely kind pal’s garage and found a tenement flat on Gumtree in Glasgow’s south side.

Suddenly, our large Victorian home and sizeable garden had no longer seemed right for us. While I have wonderful memories of numerous children’s parties on the lawn – the trees strewn with bunting, and 20-odd kids charging about in pirate costumes – the only one who used it these days was the dog. I shuddered at the thought of our sons’ empty bedrooms becoming stale with dust, their posters slowly peeling. As they were embarking on a new adventure, then why shouldn’t we?

It turns out I am not alone in feeling positive about this stage. In a recent survey only a quarter of parents said they felt sad at their children leaving home, with a third describing themselves as "relaxed" about becoming empty-nesters. In fact, we have a name – Hens (Happy Empty Nesters) – and relish the prospect of more travel and spontaneous fun. Yes, I miss my sons hugely and think about them every day – but, on the plus side, we now have the time and energy to do the things that had been put on hold during the child-rearing years. The survey, by retailer Cotton Traders, revealed that empty-nesters enjoy a reduced workload in the home, more couple time with a partner – as well as regaining control over the TV remote.

If anything, I have experienced a sense of nostalgia, which is very different from sadness. I can reflect upon the fun times we had as a family – the holidays, parties, the fishing and camping trips – and feel a sense of pride that we managed to scramble through. I can also forgive my less than spectacular moments – like sending my sons off to an all-day scout hike without any lunch, and throwing an adult tantrum (over what, I can’t remember) which involved me throwing my handbag across our hall and a hail of coins clattering to the stone floor. As for a sense of loss, at least our sons have chosen to further their studies in Scotland. As one pointed out: "Look, Mum, it’s not as if I’m in China."

Plus, we still have one teenager at home who, like us, is relishing her first taste of living in Glasgow – a city in which we have long yearned to make a home. As one friend, whose son started at St Andrews University, puts it: "It would seem wrong to go on about missing him when he’s having the time of his life. It’s about him – not me. And if I feel at a bit of a loss occasionally, then it’s up to me to fill that gap."

In fact, the "gap" feels like an opportunity to live life differently. While I loved raising our family in rural Lanarkshire, after 16 years in the country I was ready for the hustle and bustle of a city again. I am enjoying discovering parks and coffee shops, seeing films at the drop of a hat and – silly though it sounds – nipping about on the Subway. I spent my 20s and early 30s in London and have always been a city person at heart.

Plus, being in a new environment has set my brain whirring, and recently I found an urge to draw again. I had always enjoyed playing about with pens and paint but raising three children – as well as working full-time as a writer – meant there was precious little spare time. When my sons left for uni, they packed up their clothes, books and a bevy of gadgets – but for some reason had no interest in taking their childhood stamp albums (freshers' week clearly held more appeal than philately: I cannot understand why).

We had started collecting as a family, having discovered a stamp shop in Quimper, southern Brittany, close to the farmhouse we rented several times for our summer holidays. It seems so quaint now, but a decade ago my kids were thrilled to sit around the kitchen table in the evenings, nibbling at strawberry tarts from the patisserie and bartering over the packets of stamps we’d bought for a euro or two.

The albums contained dozens of beautiful, delicate bird stamps and I wondered what to do with them. I started drawing bird cages around the stamps – simply because I love delicate wire work, and not due to any desire to cage my sons. A friend suggested selling them and, as it didn’t feel right to ask for proper money – I am very much a doodler, not an artist – I decided to offer my birdcages for a £10 donation to Save The Children, as they are running an emergency Syria appeal. In September alone I raised £1.300, and plan to keep "birding" for as long as people want them.

While it’s fantastic to raise cash for charity, my nutty work-avoidance bird project has also highlighted that, when children fly the nest, it can open up new opportunities. After a day of battering a keyboard, writing my books, there’s something immensely satisfying about holding a pen and doing something visual, rather than with words. Of course, the dining table is now cluttered with paper and paints and the scattering of stamps on the sofa means there’s nowhere to sit.

In fact, it’s not so different from living with teenagers after all.

Fiona’s latest novel, As Good As It Gets?, is published by Avon. If you would like a bird you can donate to Fiona’s Just Giving page for Save the Children at https://www.justgiving.com/Fiona-Gibson12/ or contact her directly at hello@fionagibson.com