Preston was a scandalous presence among the Happy Valley set, noted both for her beauty, as well as her wild lifestyle, which included partying all night long, rising from bed during dinnertime and drug abuse. Preston had become a notorious drug addict by that point; taking heroin, cocaine and morphine. She was nicknamed "the girl with the silver syringe", due to her habit of always carrying with her a syringe with which she injected herself. She was reported to often take out the silver syringe to inject herself, oblivious to onlookers. Swedish Baron Bror von Blixen-Finecke's second wife Cockie once remarked of Preston: "She's very clever with her needle". Preston was one of the clients of Frank Greswolde Williams, the main drug dealer of the Kenya colony, until his death in 1932. Whenever she was out of morphine, she sent a plane to pick up new supplies.