Queen Elizabeth II had two “hidden” cousins named Nerissa (left) and Katherine Bowes-Lyom (right) who were both born with severe learning disabilities.
Daughters to John Herbert Bowes-Lyon (brother of the Queen mother and uncle to Queen Elizabeth II) and his wife, Fanella, Nerissa was born in 1919 and Katherine was born in 1926.
Following the death of their father in 1930, the sisters were admitted to the Royal Earlswood Hospital, a mental health institution located in Redhill, London. The Royal family then declared that they both were dead. In reality the sisters were alive and spent the next several decades in the hospital. On April 6, 1987, British tabloid newspaper, The Sun, broke the story with the headline: “QUEEN’S COUSIN LOCKED IN MADHOUSE.”
Nerissa died at age 66 in 1986. When the hospital shutdown in 1997, Katherine was moved to another home in Surrey. She died at age 87 in 2014. There was no evidence that any of the royals visited them.