NO.
John F Kennedy
Jean Kennedy Smith is JFK's only surviving sibling.She was his youngest sister, and she is now 81 years old.
John F. Kennedy at 46, followed by James Garfield at 49. They were both assassinated in office. The youngest president to die a natural death was James K. Polk who died of cholera at 53.
Kennedy was the youngest elected US president.
Oldest was Ronald Reagan, who was elected at age 69. Youngest was John F. Kennedy, elected at age 43. However, Theodore Roosevelt assumed office at 42 years old (he was not elected).
John F. Kennedy's siblings were Joe Kennedy, Rosemary Kennedy, Kathleen Cavendish, Eunice Kennedy Shriver, Patricia Kennedy Lawford, Robert F. Kennedy, Jean Kennedy, and Ted Kennedy.
John F. Kennedy (46)
John F. Kennedy
youngest
youngest
Edward M. "Ted" Kennedy
John F. Kennedy and Jacqueline Kennedy had four children in order from oldest to youngest: Caroline Kennedy, John F. Kennedy Jr., Patrick Bouvier Kennedy (who died at 2 days old), and Arabella Kennedy (who was a stillborn).