My brother and I were children in the 1950s, teenagers in the 1960s. Like most children, our parents encouraged us to read what were generally considered to be 'good books', those written by well-established writers and published long before we were born. Our primary school didn't have novels you could borrow and there was no bus route to the local library, but we were bought books as presents and sometimes they were sent by my aunt in America - not hundreds of them, just enough to fill a bookshelf each.

I still own most of my childhood books and have inherited my brother's; cheap, cloth-covered hardbacks published by Dean and Sons Ltd or Thames Publishing Company and marketed as Regent Classics. The American books had better quality paper and plenty of illustrations which I adored. Few of the British ones had any pictures at all. If you were lucky, there would be one ludicrously anachronistic picture opposite the title page - my Regent Classics copy of Jane Eyre shows her in a long baby-blue dress with a blonde 1950s-style ponytail tied up in a pink bow, talking to Rochester, who looks like Cary Grant in a tuxedo. I thought it was great.

Apart from a shared collection of Enid Blytons, I don't remember reading my brother's books and I'm sure he didn't read mine. On his shelf were copies of Robinson Crusoe by Daniel Defoe, Our Friend Jennings by Anthony Buckridge, Jules Verne's Around the World in Eighty Days, The Story of Davy Crockett by Enid Lamonte, Mark Twain's The Adventures of Tom Sawyer, The Man in the Iron Mask by Alexander Dumas and Robert Louis Stevenson's Treasure Island. On my shelf there were much read and much loved copies of all of Louisa May Alcott's Little Women books and her lesser known novel An Old Fashioned Girl, Anna Sewell's Black Beauty, Susan Coolidge's What Katy Did and What Katy Did Next, Jane Eyre and Wuthering Heights by Charlotte and Emily Bronte, Heidi by Johanna Spyri, the sequel Heidi Grows Up written by her translator Charles Tritten, and a clutch of boarding school stories.

Books for boys and books for girls. While my brother had books of war, derring do, adventure and brave encounter, I had stories of family life, self-denial, love (without sex, of course), and personal stories of triumph over tragedy - the domestic dramas. In his stories, boys or young men went, often alone, to have adventures, wage wars or make fortunes. They were being taught how to be the arbiters of their own destiny. In my books, the girls either stayed at home or, if they were homeless, which was frequently the case, found a new one and almost always ended up as happy homemakers. There might not have been killings but there was certainly plenty of suffering and death in haunting, tear-stained scenes, most affectingly Beth March's in Little Women and Helen Temple's in Jane Eyre. The wars fought in my books were small, personal battles against character traits considered unsuitable for girls: hot tempers, ambition, too much cleverness or jealousy. Sometimes there were brave, dignified fights against injustice, like Jane Eyre's against her aunt and Mr Brockiehurst, or Katy Carr's calm handling of her distress when she was wrongfully accused of behaving provocatively towards the boys in the next-door school, and it was wonderful when my heroines won through, although there was often a heavy price to pay for their victory.

What lived with me most in these books were quirky odd details of personality, atmosphere and location; things which caught my imagination and stayed there. I remembered Heidi's meals of bread, melted cheese and fresh goat's milk which she drank out of bowls and her hayloft room with its round window looking out over the starry Alpine sky. Katy Carr's naughtiness at school, her climbing into next door's playground to retrieve her school hat and getting caught. Katy's cousin Helen with her calm saintliness, smooth shiny hair and beautiful presents. Jane Eyre in the red-room, her horrible bullying cousins, those terrible injustices at school meted out by cruel unthinking adults. Jo cutting off her hair and her disappointing failure to marry Laurie. Amy's brief passion for pickled limes; burning Jo's stories. Sweet Beth being given a piano with gold silk and candelabras, nearly dying but 'turning' and then finally leaving us all to cry for her. And Mary in the secret garden with just her friends, not a single adult knowing where she was.

As a child reader, I didn't see these books as old-fashioned or out of my time because I thought that books were always from a different place. It didn't occur to me that anyone might be writing about girls just like me, and my other reading (posh girls playing lacrosse at boarding school) confirmed this. It would have been impossible to imagine a book about a Jewish girl growing up in a London suburb, and I'm not sure I would have wanted to read one anyway. The books I loved were as different and distinct to me as each one was to its writer and I was only vaguely aware that there were any similarities between them. I think I understood that they were all about girls in families or searching for one and that a lot of these children seemed to be orphans, but I had no interest at all in comparing Heidi to Katy or Jo to Jane. I suppose if asked, I would have been able to say that all these girls were strong minded, battling with their own naughty and rebellious natures. I enjoyed this but since I was being brought up to be more of a Meg than a Jo, it was a secret relief to me when these lively rebellious girls grew up into sweet, submissive women. I certainly didn't notice that disability, illness (particularly paralysing illness) and cure are central to many of these stories, but this isn't surprising since most literary critics and commentators have similarly failed to notice it, or considered it, at best, worth only a passing remark.

I began to look at my books differently when I re-read them with my daughters. What made my reading different was not the passage of time, because my world as a child had been as different as my children's from the world of Katy, Mary and Pollyanna. They loved the stories as much as I did and for the same reasons but they brought a new knowledge to their reading. Since a road accident when they were very young, I have used a wheelchair and have legs which 'don't work'. None of us see me as a poor invalid who has to be taken care of, but we are also aware that no wheelchair smashed by a jealous goat-herd (Heidi), magic healing place (The Secret Garden), change of personality (What Katy Did), or miracle cure in a New York hospital (Pollyanna) is going to get me up and running about again.

At one point in my research for this book it felt like there was hardly a girls' novel since 1850 which didn't have a character who at some crucial stage defied their guardian and fell off a swing or out of a sled, became paralysed through tipping out of a carriage or was suffering from some nameless, crippling illness from which they could, indeed must, be cured. From the 1850s, up until very recently (and even now writers kill or cure their disabled characters with worrying ease), there were only two possible ways for writers to resolve the problem of their characters' inability to walk: cure or death.

This cure is somehow so central to the outcome of the story, so expected, that I and generations of readers and countless commentators have failed to notice it or remember it as significant. But even as we failed to take account of it, we were storing up enough perceptions and ideas about disability to last a lifetime. We were learning that: (1) there is nothing good about being disabled; (2) disabled people have to learn the same qualities of submissive behaviour that women have always had to learn: patience, cheerfulness and making the best of things; (3) impairment can be a punishment for bad behaviour, for evil thoughts or for not being a good enough person; (4) although disabled people should be pitied rather than punished, they can never be accepted; and (5) the impairment is curable. If you want to enough, if you love yourself enough (but not more than you love others), if you believe in God enough, you will be cured.

Strong stuff then and strong stuff even now.