Lavender became the ward to Dr. Anton Murik in 1970 according to a court report that she is the daughter of a second cousin to the present Laird. The court reports also document that his father and mother were killed in an air crash, and she will earn her inheritance come her twenty-seventh birthday. Along with this, it mentions that Murik allows her to model on special occasions with watchdogs.
In an attempt to arrange a coincidental meeting with Murik at the Ascot Gold Cup, James Bond effortlessly manages to remove a pearl necklace around Peacock's name. Earlier, Bond had been briefed that the pearls (valued at £500,000) were a wedding present from her father to her mother, and Murik forbid her to wear them. When Lavender realizes her pearls are gone, Bond shortly notes he had found the pearls by the swine at the racecourse. He eventually bets on Murik's China Blue to win, and tells Murik of his profession as a former soldier and mercenary-for-hire. Murik has Bond invited to his castle to participate in the Highland Games.
That same night, when Bond is eavesdropping on Murik's conservation with Franco and shortly after Mary Jane Mashkin leaves, Lavender enters the room. There, she asks for Bond to call her by her nickname, "Dilly", in reference to a song, "Lavender-blue, dilly-dilly...". Peacock strikes up a conservation with Bond about Murik hiring people "to do the dirty work", and putting Bond at risk. She later changes the subject to how she brings trouble on people because she is "beyond salvation". Eventually, she pleads for Bond to help her escape Murik Castle which she feels imprisoned to. Bond eventually agrees, and she leaves the room.
After Bond has been informed about Operation Meltdown, and hired to kill Franco, he leaves Murik Castle with assistance from Lavender. He is eventually captured and interrogated by Murik and Mary Jane Mashkin, and later transported to Perpignan, France where he escapes them at an airport. At a fashion show in the Palais des rois de Majorque where Lavender is modeling an elegant dress, Bond kills Franco, who accidentally shoots a gelatin capsule at Mary Jane originally aimed for Lavender. Knowing Lavender as the true heir of the Laird title, Bond questions Murik about this, in which he replies that when he was about to surrender the Laird title to his half-brother, he and his wife, which gave birth to Lavender, suddenly died without seeing the official documents confirming they are legal heirs to the Laird title.
Shortly after the relevation, Bond is tied aboard Murik's Lockheed-Georgia C-14 Starlifter. Bond releases himself, knocks Murik unconscious, and foils Murik's ransom plot calling off the terrorist squads. Caber later engages in a fierce battle with Bond that ends with Lavender slitting Caber's throat, and his body falling out of the ramp of the plane. When Bond lands the aircraft, he discovers Murik has escaped, and in an attempt to validate Lavender as the true Laird later that night, Bond theorizes to M and Bill Tanner that Murik is returning to his castle to destroy the documents.
After Murik is killed, the official documents reveal Lavender's true name as "Lavender Murik", and earns the title, "Lady Murik of Murcaldy". Sometime later, she is accepted into a major agricultural college, where she intends to study estate management. Promising to visit her again, Bond sees Lavender off as her train heads down the trail tracks.
Lavender is revealed to be managing her Scottish estate with great success.