A happy child, she played hockey and was a member of her local brownie troop. After her mother started a successful party-supply company, the family moved to the affluent village of Bucklebury, where Kate went to a local private school.
Like girls across England, the ones at Middleton's school had set their sights on young Prince William.
"You'd overhear them talking about it," said Kingsley Glover, a fellow student at St. Andrews Prep School. "You'd hear them saying, 'Oh, wouldn't it be great if you ended up marrying the prince.'"
The next year, Middleton entered one of England's most exclusive and expensive boarding schools, Marlborough, where she blossomed into a beauty and was popular with the boys, but never went too far.
"She's always been dignified even when she was at school. She's always been one of those who, yes, she'll join in the fun but she'll never put a toe out of place," author Morton said.
At Marlborough, Middleton met many young aristocrats, including several of William's polo-playing friends who now were her friends, too. Middleton's world was getting bigger and more blue blooded while William's was falling apart.
His parents' crumbling marriage was the top story in the tabloid press.
As photographers chased Princess Diana through the streets of Paris Aug. 31, 1997, the car in which she was traveling crashed in the Pont de l 'Alma tunnel. Princess Diana would die soon after being cut from the mangled wreckage and Prince Charles would be left to deliver the news to William and Harry that their mother was dead.
After his mother's death, speculation surrounding the paparazzi's role in the tragic car crash only fueled William and Harry's distrust of the media.
Colleen Harris, who became press secretary to Prince Charles, Prince William and Prince Harry after Diana died, said, "I've worked for prime ministers and given advice, and they were very willing candidates, whereas William was always a very questioning candidate. They were quite suspicious and really didn't want to engage that much."
As soon as William graduated Eton, he was able to escape from the gaze of the paparazzi and head off to his gap year, a year many British students take before heading off to college. It was a time for him to explore the world and contemplate his future.
But the future held something he couldn't imagine. A year later his life would intersect with Kate Middleton's: she the representative of 100 years of social aspirations, he an heir to a throne, scarred by scandal and divorce. They would form a bond made in childhood dreams.
For more on Prince William's and Kate Middleton's childhood years, tune into a Barbara Walters special. "The Royal Wedding: A Modern Fairytale" April 18 at 10 p.m. ET.