Prior to the pilot
Brenda is the oldest daughter of a wealthy psychiatrist, Bernard Chenowith, and psychologist Margaret Chenowith. During her childhood, Brenda's parents were sexually open to their children, along with being promiscuous, often deviating from their respective marital partner. Also during her childhood, Brenda was discovered to have an IQ of 185, and, as a result, was the subject of a study by psychiatrist Gareth Feinberg, published as the best-selling book Charlotte Light and Dark, a book that would repeatedly haunt Brenda throughout her life. In fact, as a child Brenda realized she was being observed and began studying mental disorders and would fake symptoms to spite the doctors. At one point in her life, Brenda planned on attending Yale University, but opted to remain at home in California and attend UCLA when her troubled brother, Billy, ostensibly attempted suicide.
During the series
Brenda is first seen exiting the Los Angeles airport with Nate Fisher. The two have sex in a janitor's closet before Nate receives news that his father has died. The two part ways but continue their sexual relationship. She is now a shiatsu massage therapist, operating out of her home. Her relationship with Nate continues to grow more serious until Billy emotionally invades her relationship. Billy is a photographer who is often in and out of mental institutions. He exhibits extreme possessiveness over Brenda and even begins stalking her and Nate. The two share matching tattoos on their lower backs, Brenda's baring the name Nathaniel, Billy's being Isabel. These names are taken from their favorite childhood book series Nathaniel and Isabel. Billy's obsession with Brenda eventually spirals out of control when he quits taking his medication and removes his tattoo by cutting his skin off. He attempts to remove Brenda's tattoo before she knocks him unconscious and has him institutionalized.
The next summer Brenda decides to return to college and begins the process of writing a novel. Her attraction to Nate has dwindled and she soon finds herself fantasizing about men outside of her relationship. Nonetheless, she proposes to Nate mid-season, and opts to stay with him, despite his admitting to a brain condition that may cause him to have a stroke at any time. Sex with Nate has all but subsided when Brenda begins a friendship with a client who is a prostitute. Brenda finds herself inspired by her new friend and eventually performs a handjob on one of her clients. Brenda then begins having more random encounters with men outside of her relationship with Nate until it escalates into sexual addiction. Later Nate admits that he cheated on Brenda with Lisa, an old friend from Seattle, and the infidelity resulted in Lisa becoming pregnant. Brenda begins having sex in public areas, attending sex-themed parties and inviting strangers into her home. She details all of these accounts in her novel and Nate eventually discovers that Brenda's writings are not fictional. The two argue before Nate ends the engagement and storms off. Nate and Brenda have one last meeting, Brenda admits her sexual addiction and asks Nate if she can be there when he undergoes brain surgery. He refuses. Brenda packs up her things and leaves her home.
Brenda is next seen returning to Los Angeles after a lengthy absence. The reason for her return is initially unknown, but Brenda seems to be fully cured of her addictions. She makes amends with Nate, but discovers that he is now married to Lisa. Later, Brenda's father dies of cancer, three months after being diagnosed. Nate attends the funeral with his new daughter, Maya, much to Lisa's chagrin. Brenda is staying with her mother, but soon moves out and moves in with Billy, however, she quickly departs from Billy's when he attempts to kiss her. She begins a friendship with Joe, a man who lives across the courtyard from her at her new apartment complex. Things grow complicated when Nate and Brenda share a kiss and even more complicated when Lisa goes missing without a trace. During this time, Brenda assists Nate's sister, Claire, in receiving an abortion. Lisa eventually turns up dead and Nate shows up at Brenda's doorstep badly beaten.
By this point, Brenda and Joe have developed a relationship. Things escalate quickly and the two move in together and begin trying to have a child. Brenda reverts to old habits when she begins sleeping with Nate out of fear of committing to Joe. She admits to sleeping with another man to Joe, and the two attempt to stay together despite Brenda's infidelity. Joe walks in on Brenda and Nate about to have sex and breaks it off with Brenda, permanently. Shortly after, she and Nate get back together and Nate moves in with her. Brenda becomes a surrogate mother to Maya but still desires a child of her own. Nate shows little interest in having another child. Lisa's sister, Barbara, shows considerable distaste in Brenda assisting Nate in raising Maya and eventually learns that Nate may have filled Lisa's urn with different ashes. She threatens to take Maya away, but it is revealed that her husband may be linked to Lisa's death before he shoots himself. Following these events, Nate proposes that he and Brenda get married and have a child.
Brenda soon becomes pregnant, but miscarries the day before her wedding to Nate. She opts to continue with the wedding, but soon begins to have doubts if she will ever be able to have the normal family she desires, due to her past indiscretions. Brenda begins work as a therapist. Conflict arises when Brenda debates revealing to Maya that she is not her biological mother. Nate believes it is too early to expose Maya to such things. Brenda becomes pregnant again and this time the baby is seemingly healthy, until the doctors begin to worry that the baby may develop Down syndrome or spina bifida. Nate pressures Brenda into having an amniocentesis and if the results are positive, considering an abortion, but Brenda resists. She and Nate face even more turbulence when Nate begins a friendship with Maggie Sibley and shows an interest in Quakerism, much to Brenda's displeasure. Nate soon begins an affair with Maggie, but suffers a hemorrhage after his first encounter with her. He goes into a coma, but wakes up with Brenda at his side. He seems to be doing better, and breaks up with Brenda, most likely with the intention of beginning a relationship with Maggie. He dies before he leaves the hospital, leaving Brenda pregnant and alone. She grows scared and leaves Maya with Ruth, which later leads to conflict when Brenda wants Maya back. Brenda then confides in Billy, who had recently broken up with Claire. She soon feels uncomfortable with the incestuous overtones of their relationship and asks him to leave. She delivers a premature baby girl, Willa Fisher Chenowith, who eventually grows healthy enough to leave the hospital.
Brenda later becomes a professor and scholar, particularly in the development of gifted children. She marries a man named Daniel Nathanson and has another child, Forrest Nathanson. She seemingly remains close friends with Claire Fisher throughout her life. She dies at the age of 82 in 2051 of natural causes, suffering from early signs of Parkinson's disease. The audio commentary jokingly suggests that Billy bores Brenda to death as he is heard still talking about his failed relationship with Claire.
She remained an open, outspoken atheist throughout the entirety of the series.
- "Brenda Chenowith was born July 19, 1969 and died at the age of 82 at home. She earned her Masters Degree in Social Work at California State University of Los Angeles and a PhD in Theories of Human Behavior at University of Southern California.
- Brenda wrote several books about the role of the gifted child in family development. She is considered to be one of the most distinguished scholars in that field of study, adding several courses to the Social Work curriculum at USC. She developed research methodologies to conclusively prove the link between deviant human behavior and fetal alcohol exposure. As a child, Brenda was the subject of the book "Charlotte Light and Dark" by Gareth Feinberg, PhD.
- Brenda will be dearly missed by her beloved children Maya Fisher, Willa Chenowith, and Forrest Nathanson, her loving husband Daniel Nathanson, and her brother William Chenowith of Malibu. Private services will be held Wednesday March 9th at Deep Creek Nature Preserve. In lieu of flowers, donations may be made to a charity of your choice."