Recently I spent two months in France as the winner of the Robert Louis Stevenson 2000 award for writers. I stayed at Hotel Chevillon in Grez-sur-Loing, a picturesque riverside village set in the Fontainebleau forest, just south-east of Paris. In the late 19th century, Chevillon was home to an international community of artists and it was there that Stevenson first met Fanny Osbourne, a vivacious American 12 years his senior. Later he would follow her to America where they married.

I loved the story of the star-crossed lovers' first meeting in Chevillon. But there'd be no such distractions for me; a fortysomething novelist with a loving partner and a tribe of grown children left behind in Glasgow. I was there to write, in solitude.

I worked hard but missed switching off my computer and strolling along to the nearest cafe bar at 5 o'clock every day. I found a Tabac in the village where I could have coffee or cognac, depending on how my writing had gone that day. The other customers quickly dismissed me as one of les artistes and, apart from the occasional "Bonjour Madame", I was left alone.

It was in the Tabac that I first observed that the woman who ran the place with her husband and daughter was approximately my age. Dressed for work in trousers and shirt, she looked elegant, chic and sexy. One day her granddaughter, an angelic three-year-old named Ophille, made a grand entrance, twirling around in her new summer frock. Madame applauded loudly: "Très belle, ma chérie ... Jolie enfant."

The child glowed. And I realised that, determined that my own little granddaughter would never be "just a pretty face", I made a point of telling her she was a big clever girl but never told her she was beautiful. Would she ever, like the luminous Ophille, glow with the knowledge of her own loveliness, handed down from her grandmother like a precious heirloom or family recipe?

I took the 10-minute bus ride to Fontainebleau. After a visit to the palace and a peek at Napoleon's tiny bed, I wandered through the town. In Rue de la Come I found the English bookshop and coffee bar. I bought a secondhand volume of Virginia Woolf's letters and went out with my coffee to a pavement table. My book lay neglected on the tabletop as I gazed at the women passing by, the women around me. Some of them were my age or older, but like Madame back in Grez, chic and sexy. The phrase that sprung to mind was well cared for.

I hadn't cared for myself in that way for a long time. But when and why had I stopped? A lifelong feminist, I believed Gloria Steinem had the right idea; there was damn-all wrong with female adornment, as long as it was my choice. I wore jeans and white shirts, tailored jackets and boots, and I had long, streaked, tousled hair. One night I was introduced to Billy Connolly in a Glasgow bar and he said I had the look of Goldie Hawn. My daughter said: "It's well seen he's a comedian." I laughed.

In my early 40s I began to put on weight, middle-aged spread, and with my more voluptuous figure, I would have put the Big Yin more in mind of the chunky one from Status Quo if I'd stuck with my rock chick look. But I couldn't find a new look for me. Faced with a high street lined with Miss Selfridge, Top Shop and Kookai, a little voice in my head would whisper: "There's nothing for you here. Grow up, Maggie, you're a granny."

And I listened. I had my hair cut and lived in loose tops, baggy pants and long skirts. I hardly ever went shopping and when I did I would buy clothes and toys for my grandchild.

So why hadn't these middle-aged Frenchwomen given up? And where did they buy their seemingly effortless style? I discovered the town was free of shops selling only minuscule garments in size six with the midriffs missing. Instead there were little boutiques and lingerie shops. I found Monoprix with an entire floor selling affordable clothes and cosmetics to suit me. Yes, middle-aged, size 14 on a good day, wee granny me. I went back to Grez with my literary letters, lacy underwear, a linen shirt and a lipstick.

In Grez I made some friends, Corinne and Françoise, both over 50 and both stunning. Corrine, a vivacious redhead, had, like me, lived in Ayrshire in the late 60s. We discovered we had gone to the same dance halls. Françoise had been an au pair in London around the same time and had lived in Aberdeen. I visited their homes for lunches and in the early evenings for aperitifs. I will never forget Corinne, just back from work, shrugging out of her raincoat, kicking off her shoes and saying: "Would a glass of champagne be OK?"

The three of us visited Chambrolle chateaux and museum de parfum. I bought a Salvador Dali fragrance in a bottle shaped like a man's nose and a woman's lips. For myself. I was having fun. Lingerie, perfume and 5 o'clock champagne were all very pleasurable and I wanted more.

I stopped sitting on my hands and began giving myself regular manicures. I had my hair restyled and coloured, with Françoise relaying instructions to the stylist. I bought a soft leather bag and some silk scarves from a street market. The French have no youth culture that tells women it's fine to grow older as long as you don't look it, dearie. I had stayed young-looking for a long time. I was a teenage bride, a young mother and as a mature student I had mixed with younger people, bought my clothes from Oxfam and hung around the Union just like them. And I was confident, known around the English department as "that cocky bitch".

But when I began to look my age, I lost that confidence. I was no longer a size 10 and no one mistook me for my children's sister any more. Germaine Greer wanted me to wait around for cronehood and the media presented with me Tina Turner for a role model. Not fancying either, I simply stopped paying attention, wimped out and became invisible.

In France I began to enjoy "myself" again. I visited Paris and as I wandered around with my copy of Women of the Left Bank, searching for the houses where Djuna Barnes, Gertrude Stein and Anaïs Nin had lived, I noticed that men were looking at me. After the first few times, I stopped turning round to see if there was a 17-year-old nymphet behind me.

The day before I left France, I went out to lunch with Françoise and Corinne in Fontainebleau. They gave me gifts; a bag full of Darphin beauty products and the Alexandra Lapierre biography of Fanny Stevenson.

Now back home, I'm planning a novel about Stevenson and Osbourne's first meeting, which means I will have to go back, very soon. When little Aimie comes to visit, we boogie to her special song, Brown Eyed Girl, and I tell her that she is a devastatingly beautiful big clever girl. And that she takes after her grandmother.

Sitting Among the Eskimos by Maggie Graham is published by Headline at £9.99.