Aunt Sophie's diamonds1978

Claudia Milmont has lived most of her joyless life with her grandparents, though her mother enjoys the fringes of society in London. When Claudia’s Aunt Sophie dies, a whole new world opens up for her. Cantankerous Sophie has instructed that her diamonds be buried with her—and Claudia is determined to help her cousin retrieve them. But the charming Sir Hillary Thoreau, a nonesuch, is co-executor of Sophie’s will and he’s keeping a sharp eye out for any mischief—and for Claudia, too, it would seem. Regency Romance by Joan Smith; originally published by Fawcett