She was born at the beginning of the Great War, the daughter of a Professor of English at the University of Buenos Aires and his wife, both Roman Catholic converts, and her whole life was testament to her absolute, unswerving faith. Schoolgirl lore had it that she had been jilted at the altar - something which would have amused her latterly. But the truth was that she became a nun aged 20, turning down a place at Newnham College, Cambridge, in favour of her vocation. It was not until she took a first class external degree from London University in 1937, and, in 1949, a theology diploma, that her formidable intellect (she thought reading the Russian classics in translation was a cop-out) was recognised formally.
She was educated from the age of six by the order of teaching nuns which she eventually joined, the Institute of the Blessed Virgin Mary, founded by Mary Ward in the 17th century. But it is as the headmistress of Ascot that she will mainly be remembered, for being there under Mother Bridget was not something easily forgotten.
Being at an exclusive, single-sex, strict, convent boarding school during the late Sixties and Seventies was a curious experience. Bob Dylan sang, "The times they are a-changin' ", but at Ascot life went on much as it might have done in the Middle Ages. Mother Bridget presided over rows of girls in black mantillas who went to Mass at least three times a week, wore two pairs of knickers, dropped everything to say the Angelus twice daily and were taught to be deeply suspicious of all men except the priest.
She was a figure of enormous authority, and being summoned to "Budge's" study was a terrifying experience, the anticipation of which reduced pupils to tears. But the result was often rather unexpected. Summoned in once for some misdemeanour, I found her reading a book of French poems. She gave me one to learn as a punishment, then asked if I could play bridge. I could not, so along with a few others she tried to teach me. It was only afterwards that someone pointed out that Mother Bridget probably thought the game would be useful as she was hoping most of her girls would "marry into the Foreign Office".
Mother Bridget was keen on achieving a good academic record for the school. But this desire was tempered by her belief that women were really meant to be mothers or nuns - and the Ascot results reflected this. Mother Bridget valued a good marriage as much as a good degree and, as this became an increasingly unfashionable view, she found herself out of kilter with her times. In correspondence I had with her after leaving school, in which her wit and humanity shone through, it was clear that, although she accepted the mobile phone and the working wife, she felt civilisation was being diminished.
Wonderfully unpolitically correct, Mother Bridget was open in her likes and dislikes. She never hid her delight in people she considered socially smart and the school benefited enormously from her ability to charm people into funding new facilities. Stories abound of her sweeping more ordinary parents aside to make way for President Marcos, whose daughter Irene always won the dressmaking prize, and she loved having Princess Caroline of Monaco and the Spanish princesses under her care. It upset her when she had to reprimand the vivacious and naughty Giancarla Forte. Many girls found her pleasure in the fact that their houses were open to the public endlessly amusing.
But she also took particular delight in expanding all her pupils' minds. From her ghost stories to her literature lessons, she brought unparalleled excitement to the English language. Shakespeare enthralled her and once, during a violent storm, she made the whole school read the tempest scene from King Lear. Her knowledge was encyclopaedic and she would grow frustrated if her class was idle, cajoling and teasing brains into action. Her intellectual energy was astounding and remained remarkably unblunted. Praise was not often forthcoming, but when it was you treasured it.
Out of the classroom Mother Bridget presided over a curious regime. Immensely cultured, she had little time for the ordinary. Girls in whom she took a particular interest were treated as adults. I was always in trouble for reading late at night with a torch; Mother Bridget had my room changed and I was left in peace to read at will. But once, caught washing my hair when not authorised, I was left devastated by a lecture on vanity.
The school, under her iron grip, was a difficult place in which to be an adolescent girl. The physical horrors of puberty were treated with incomprehension and some pupils found it difficult to forgive Mother Bridget for failing to get to grips with some of the school's stranger practices. Warts were treated with a knife and smelling salts, periods with lectures on evil, pain was to be offered up "for the Holy Souls", broken legs went unobserved.
But, when she retired, something fine and uncompromising was lost to St Mary's. Sister Bridget (she had been, ever since the Second Vatican Council, "Sister" Bridget, even if no pupil thought of calling her anything but "Mother"), moved to IBVM convents at Cambridge, then Hampstead, then finally to the Bar Convent at York, where her teaching work continued. Her faith remained solid, unchanging and unchanged.
For girls who found themselves under her charge, her influence, for good or ill, will remain with them always. One of my favourite stories about Mother Bridget concerns a young member of the school who, on finding a worm in her orange, let out a scream to wake the dead. The whole dining- room was silent as the screamer was commanded by Mother Bridget to identify herself. Eventually a small, skinny girl crept out, shaking, holding the worm and the orange. Mother Bridget looked at it, then at her. "Well," she said. "And what, may I ask, would you have done if you had found a snake?"
Bride Geoffrey-Smith, nun and teacher: born Buenos Aires 27 January 1914; entered the Order of the Institute of the Blessed Virgin Mary 1934, taking the name Sister Bridget; Headmistress, St Mary's School, Ascot 1956-76; Reverend Mother, St Mary's School, Cambridge 1976-79, St Mary's School, Hampstead 1979-85; died York 10 June 1999.