Over the course of her lifetime, she sold more than 11 million books in the UK alone.
Gibson said: “What I understand from those people who knew her well, was that she was a bubbly character and I think that came through in her writing.”
The novelist was born in Hornchurch in 1937 but her family returned to Yorkshire when she was a child.
Her great-great-grandfather was a Liberal MP for Leeds and founded The Leeds Mercury, a newspaper which merged with the Yorkshire Post.
Her grandfather went to St Peter’s School in York, and then into the church.
While in Ilkley, Dame Jilly went to Moorfield before she was sent away to boarding school at the age of 11.
A spokesperson for the school said: “The Moorfield community was saddened to hear yesterday of the death of Dame Jilly Cooper.
“She was one of Moorfield’s most famous pupils, having attended the Ilkley independent preparatory school during the war years of the 1940s and thereafter.
“In 1980, Jilly came back to visit to help celebrate the school’s 50th anniversary. She remained a loyal supporter of Moorfield long after she left and had fond memories of her formative years at the school.”
Dame Jilly described the school as “wonderful and happy” with “dazzling” teaching but admitted she was poor at games.
At the time she was a pupil, the school was based at the founder’s home on West View before moving to its current site in 1968.