From Amazon -
"At just six days old, Mary Stuart became Queen of Scots. At just six years old she was betrothed to the Dauphin Francois, the future King of France. Reluctantly leaving Scotland, Mary is raised in the decadent French court in preparation to become the Queen of France. But her reign with Francois is short-lived. Widowed at just eighteen years old, Mary is once again forced to leave her home to return to Scotland. Now a Catholic queen of a Protestant country, Mary must rule with caution and choose her next husband prudently..."

I was addicted to Jean Plaidy's novels when I was a teenager and this was one of the first ones I read.

Left in a pile of baskets in the food hall.