Rosemary Germaine (Rosie) Mole (later Rosie Lucas) (b. 11 November 1982, during the book The Growing Pains of Adrian Mole) is the much younger sister of Adrian Mole and grows up to be his total opposite, although they do share quite a close relationship. By the age of 15, in Adrian Mole The Cappuccino Years, she has become a foul-mouthed rebellious vixen, modelling her appearance on Spice Girl Emma Bunton, and wears very short miniskirts. She becomes pregnant by a boyfriend named Aaron Michaelwaite, a fact she discloses only to Adrian, and orders a realistic baby-simulator doll to prepare herself for motherhood - although she later chooses to have an abortion.
In the book Adrian Mole and the Weapons of Mass Destruction she is attending Hull University to study "Nanobiology" and has a boyfriend named Simon who is a drug addict. Once again, she confides her problems only to her brother: telling him that she has yet to begin her dissertation and needs money to support Simon's habit, whereas her parents believe she has finished a piece of original research and requires funds for a new printer. Whether or not she ever graduates is yet to be revealed.
Shortly after Rosie's birth, Pauline Mole's ex-lover Mr. Lucas claims to be her natural father. Pauline insists that Rosie is George Mole's child, and she is raised by the Moles, but the paternity issue is never definitively resolved until the family agrees to go on The Jeremy Kyle Show, where it is proven through DNA tests that Rosie is Mr Lucas' child. She then changes her name to Rosie Lucas and goes to live with him in his so-called "mansion", he had boasted to the Jeremy Kyle studio audience.