[6] A biographer wrote that Rose Kennedy did not confide in her friends and that she pretended her daughter was developing typically, with relatives other than the immediate family knowing nothing of Rosemary's disability.

[3] At age 16, Kennedy was sent to the Sacred Heart Convent in Elmhurst, Providence, Rhode Island, where she was educated separately from the other students.

Two nuns and a special teacher, Miss Newton, worked with her all day in a separate classroom.

Her reading, writing, spelling, and counting skills were reported to be at a fourth-grade level (ages 9–10).

During this period, her mother arranged for her older brother John to accompany her to a tea dance.

[10] Diaries written by her in the late 1930s, and published in the 1980s, reveal a young woman whose life was filled with outings to the opera, tea dances, dress fittings, and other social interests.

For some time past, I have been studying the well known psychological method of Dr. Maria Montessori and I got my degree in teaching last year.

[3][better source needed] When Kennedy was 23 years old, doctors told her father that a lobotomy would help calm her mood swings and stop her occasional violent outbursts.

[18][19] Joe Sr. decided that Rosemary should have a lobotomy; however, he did not inform his wife of this decision until after the procedure was completed.

[5][22] In Ronald Kessler's 1996 biography of Joe Sr., Sins of the Father, James W. Watts, who carried out the procedure with Walter Freeman (both of George Washington University School of Medicine & Health Sciences), described the procedure to Kessler as follows: After Rosemary was mildly sedated, "We went through the top of the head," Dr. Watts recalled.

[23]Watts told Kessler that in his opinion, Kennedy did not have "mental retardation" but rather a form of depression.

She initially lived for several years at Craig House, a private psychiatric hospital 90 minutes north of New York City.

[28] Archbishop Richard Cushing of Boston had told her father about St. Coletta's, an institution for more than 300 people with disabilities, and her father traveled to and built a private house for her about a mile outside St. Coletta's main campus near Alverno House, which was designed for adults who needed lifelong care.

[33] While her older brother John was campaigning for re-election to the U.S. Senate in 1958, the Kennedy family explained away her absence by claiming she was reclusive.

[20][34] In 1961, after Joe Sr. had a stroke that left him unable to speak and walk, Rosemary's siblings were made aware of her location.

[6] She was occasionally taken to visit relatives[33] in Florida and Washington, D.C., as well as her childhood home on Cape Cod, Massachusetts.

[20] Her condition is sometimes credited as the inspiration for Eunice Kennedy Shriver to later found the Special Olympics,[20] although Shriver told The New York Times in 1995 that Kennedy was just one of the disabled people she would have over to her house to swim, and that the games should not focus on any single individual.