Prone to mood swings, Baker had a mental breakdown after the death of her son, the suicide of her father, and news that her studio was shutting down.

Gladys Pearl Monroe was born on May 27, 1902,[b] in Porfirio Díaz (now named Piedras Negras, Coahuila) in Mexico, across the border from Eagle Pass, Texas.

[6] At the time of Baker's birth, Otis worked for the National Railroad of Mexico painting railway cars.

[5] In the spring of 1903, the family moved to Los Angeles County, where Otis worked for the Pacific Electric Railway Company.

[4][5] Baker and her brother, Marion Otis Elmer, had an unstable upbringing due to their father's alcoholism, frequent moves, and their parents' troubled marriage.

[10][d] She married a second time to Lyle Arthur Graves, a railway switchman supervisor at Pacific Electric, on March 7, 1912.

[17][18][19][a] Baker gave birth to a son, Robert Kermit "Jackie", followed by a daughter, Berniece Inez Gladys.

[17] As a child, Jackie fell out of the family car, suffering injuries that left him lame for the rest of his life.

According to biographer Donald Spoto, Baker visited the children once in Kentucky and then had "infrequent attempts to contact" Jackie and Berniece during their childhood.

"[28][29] Grace transformed Baker from a brown-haired "plain jane" to an attractive red-headed woman who wore stylish clothing.

In the summer of 1924, Baker met Martin Edward Mortensen, the son of a Norwegian immigrant[33][34] and a 27-year-old meterman for the Southern California Gas Company.

[37][36]Baker worked as a negative film cutter under Charles Stanley Gifford, her superior at RKO Pictures.

[41] Baker gave birth to her third and final child, Norma Jeane (later known as Marilyn Monroe), on June 1, 1926, in the Los Angeles County Hospital.

[45] Baker registered the surname Mortenson on Norma Jeane's birth certificate, using the name of her estranged husband and specifying his address as unknown.

Within two weeks of Norma Jeane's birth, Baker placed her baby with a foster family who lived 16 miles (26 km) from her,[49][51][g] Evangelical Christians Albert and Ida Bolender in the rural town of Hawthorne, California.

[52] Baker visited Norma Jeane and took her on trolley cars to the beach, picnics, restaurants, and other outings on the weekends, sometimes spending the night, but the frequency waned over time.

The Bolenders gave Norma Jeane a stable childhood and taught her proper conduct, morality, and religion.

Norma Jeane and Grace cared for her and tried to comfort her, but Baker continued to cry and failed to get the rest she needed.

[65] In January 1934, Baker had a mental breakdown in front of eight-year-old Norma Jeane, who was forced to witness her mother flailing and screaming until the police arrived.

Baker was diagnosed with paranoid schizophrenia,[51][71] and after several months in a rest home, she was committed to the Los Angeles General Hospital.

[73][74] The Atkinsons returned to England in late 1934 and initially, Norma Jeane lived with Grace's sister and brother-in-law, Enid and Sam Knebelkamp.

[75] Grace sold Baker's house in June 1935 and the Atkinsons moved to the Hollywood Hills without Norma Jeane.

[76] After living with the Goddards for a while, Doc said that he did not want to care for Norma Jeane anymore, so Grace reluctantly brought her to the Los Angeles Orphan's Home, though she would visit her frequently and bring her presents.

[65][52][51] In June 1937, Norma Jeane moved back in with the Goddards, but was frightened by Doc, who she claimed was often drunk and sexually threatened her.

In April 1946, Baker traveled to southern California by bus and Norma Jeane took her into her apartment in Ana Lower's duplex.

After several months, she had trouble adjusting to living with people and moved out of Norma Jeane's apartment.

[79] Concerned that reporters might find out about Baker's mental illness, Norma Jeane, then going by Marilyn Monroe, said that both of her parents were dead.

[85] After being transferred to Camarillo State Mental Hospital, she was released in 1967, lived with her daughter Berniece, and moved into a retirement home in Gainesville, Florida, where she died of heart failure on March 11, 1984.

In an interview with the Los Angeles Daily News, Monroe stated:[48] My mother spent many years at the hospital.

Now I help her and I want to keep helping her as long as she needs me.Over the years, Baker's relationship with her children became a subject of debate and was addressed in many films about Monroe, such as My Week With Marilyn (2011), where she is mentioned but not portrayed onscreen; The Secret Life of Marilyn Monroe (2015), where she is played by Susan Sarandon and Eva Amurri; and Blonde (2022), where she is played by Julianne Nicholson.