Kinsey Millhone was born on May 5, 1950. Her unusual first name was the maiden name of her mother, wealthy debutante Rita Cynthia Kinsey, who married Kinsey's father, Randy Millhone, against the wishes of Kinsey's grandmother, Cornelia LaGrand Kinsey (Grand), causing a family rift. Kinsey's parents were killed in a car wreck when she was five; Kinsey was trapped in the car with her dead parents for several hours before she was rescued. She then moved in with her mother's sister Virginia (Aunt Gin), the only relative to side with Rita in the family rift, although Kinsey later finds out her parents were en route to a bridge-building family visit when the accident occurred. From her Aunt Gin, Kinsey acquired various eccentricities, including a liking for peanut-butter and pickle sandwiches. In high school, Kinsey was a self-described pot-smoking delinquent. After three semesters at the local community college she realized that academic life was not for her and she joined the Santa Teresa police force. After two years, Kinsey decided life in uniform wasn't for her, either, and quit the police force to become an investigator for California Fidelity, an insurance company, where Aunt Gin had worked. Eventually, she became a self-employed private investigator, initially mentored by local PI Benjamin Byrd, who had been a partner of another local PI, Morley Shine, before striking out on her own, solving various disappearances and murders, clearing names and dodging hitmen. For some years she maintained a loose relationship with CFI, then rented premises in the offices of her lawyer, Lonnie Kingman, before renting independent office space in later years. She has an antagonistic relationship with local policeman Con Dolan, although this mellowed into a reasonably amicable truce after Dolan's retirement and they have co-operated on more than one recent case.
Kinsey is 5'6" tall, and weighs about 118 pounds. She has short, dark, thick hair that she trims with nail scissors, being generally uninterested in her physical appearance. She is, however, very particular about her teeth, and even mentions other people's good teeth (especially men to whom she might be attracted). Her wardrobe consists mostly of jeans and turtleneck sweaters, though she also owns an extremely wrinkle-resistant "little black dress" for those occasions when dressing up is unavoidable. She does, however, place a great premium on physical fitness and jogs three miles every weekday. At the same time, she has a "penchant for junk food." She also suffers from tinnitus, caused when she shot an attacker from inside a trash can. Kinsey has been divorced twice. Her first husband, Mickey, an ex-cop, appears in O is for Outlaw and her second husband, Daniel, a struggling musician, appears in E is for Evidence. In most ways, Kinsey is a loner. She has no children and lives in an extremely compact studio apartment converted from a single-car garage. Her landlord is a young-at-heart octogenarian, Henry Pitts, a retired commercial baker who enjoys creating crossword puzzles; Kinsey admits to having a crush on Henry, but also says he is the closest thing she will have to a father. Henry's family is long-lived, his siblings all being well into their 90s. When not dining on fast food, Kinsey eats regularly at a local tavern, run by flamboyant Hungarian, Rosie, who, in the course of the stories, marries Henry's hypochondriac brother, William.
Kinsey has had several relationships in the series, beginning with Charlie Scorsoni, then Jonah Robb, a police officer, and Robert Dietz, another private eye, until the later novels in which she began an affair with longtime friend Cheney Phillips, a police detective. Kinsey remains friends with Cheney after their split, as she did for a while with Jonah, though Jonah dropped out of her life increasingly after patching up his on-off marriage. Dietz on the other hand has lost touch with her completely, although Kinsey still thinks of him occasionally.
Having lived for most of her life with very few family members (for most of the series, her "family" consisted of Henry and his siblings, Rosie, and the generous-natured employees in nearby offices), Kinsey received a shock when she found out about the Kinsey clan. When she met cousins Tasha and Lisa, she realized the three are very similar in appearance. Kinsey and Tasha formed a business relationship in M Is for Malice and Kinsey was instinctively attached to Tasha's mother, her aunt Susanna, when they met. However, she has remained reluctant to become involved with her new-found family, feeling that they abandoned her when she was orphaned. However in U is for Undertow she discovers that her grandmother made strenuous efforts to foster her after the accident, which Aunt Gin concealed from Kinsey. Kinsey finally agreed to meet Grand at a family event where her grandmother, now very frail, mistook her for her mother.